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ARCTIC REGION AND ANTARCTICA ISSUES AND RESEARCH

ANTARCTICA: THE MOST INTERACTIVE ICE-AIR-OCEAN ENVIRONMENT

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ARCTIC REGION AND ANTARCTICA ISSUES AND RESEARCH

ANTARCTICA: THE MOST INTERACTIVE ICE-AIR-OCEAN ENVIRONMENT

JASWANT SINGH AND

H.N. DUTTA EDITORS

Nova Science Publishers, Inc. New York

Copyright © 2011 by Nova Science Publishers, Inc. All rights reserved. No part of this book may be reproduced, stored in a retrieval system or transmitted in any form or by any means: electronic, electrostatic, magnetic, tape, mechanical photocopying, recording or otherwise without the written permission of the Publisher. For permission to use material from this book please contact us: Telephone 631-231-7269; Fax 631-231-8175 Web Site: http://www.novapublishers.com NOTICE TO THE READER The Publisher has taken reasonable care in the preparation of this book, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained in this book. The Publisher shall not be liable for any special, consequential, or exemplary damages resulting, in whole or in part, from the readers‘ use of, or reliance upon, this material. Any parts of this book based on government reports are so indicated and copyright is claimed for those parts to the extent applicable to compilations of such works. Independent verification should be sought for any data, advice or recommendations contained in this book. In addition, no responsibility is assumed by the publisher for any injury and/or damage to persons or property arising from any methods, products, instructions, ideas or otherwise contained in this publication. This publication is designed to provide accurate and authoritative information with regard to the subject matter covered herein. It is sold with the clear understanding that the Publisher is not engaged in rendering legal or any other professional services. If legal or any other expert assistance is required, the services of a competent person should be sought. FROM A DECLARATION OF PARTICIPANTS JOINTLY ADOPTED BY A COMMITTEE OF THE AMERICAN BAR ASSOCIATION AND A COMMITTEE OF PUBLISHERS. Additional color graphics may be available in the e-book version of this book. LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA Antarctica : the most interactive ice-air-ocean environment / editors, Jaswant Singh, H.N. Dutta. p. cm. -- (Arctic region and Antarctica issues and research) Includes bibliographical references and index. ISBN 978-1-61324-402-9 (eBook) 1. Antarctica--Environmental conditions. 2. Antarctica--Geography. 3. Natural history--Antarctica. 4. Extreme environments--Antarctica. 5. Ecology--Antarctica. 6. Climatic changes--Environmental aspects--Antarctica. I. Singh, Jaswant, Ph. D. II. Dutta, H. N. GE160.A6A59 2011 919.8'9--dc22 2010046843

Published by Nova Science Publishers, Inc. † New York

CONTENTS Foreword

vii

Preface

ix

About the Editors

xi

Contributors

xiii

Acknowledgments

xvii

Chapter 1

Antarctica: Continent Dedicated to Science P.K. Purohit 1 , Soumi Bhattacharya2 and A.K. Gwal2

Chapter 2

An Insight into the Ocean-Ice-Air Interactions over the East Antarctic Marine Boundary Layer: Unique Phenomena H. N. Dutta1 , Pawan K. Sharma2, N.C. Deb3 and Laxmi Bishnoi4

13

Land-Ice-Air-Ocean Interactions in the Schirmacher Oasis, East Antarctica Khwairakpam Gajananda1 , H. N. Dutta2 and Victor E Lagun3

39

Effects of UV-B Radiations on Terrestrial Ecosystem of Antarctica and Their Defense Mechanisms Jaswant Singh, Rudra P. Singh and Anand K. Dubey

89

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

1

Ultraviolet Radiation Stress: Response and Protective Strategies of Antarctic Flora Sanghdeep Gautam and Jaswant Singh

107

Antarctic Mosses, Limiting Factors and Their Distribution Rudra P. Singh and Jaswant Singh

131

Affinities of Lichen Flora of Indian Subcontinent VIS-À-VIS Antarctic and Schirmacher Oasis Dalip K. Upreti and Sanjeeva Nayaka

149

Water Relation of Some Common Lichens Occurring in Schirmacher Oasis, E. Antarctica

163

vi

Contents Sanjeeva Nayaka1 , Dalip K. Upreti1 and Ruchi Singh2

Chapter 9

Chapter 10

Chapter 11

Chapter 12

Index

Solar Wind Influence on Atmospheric Processes in Winter Antarctica O.A.Troshichev , V.Ya.Vovk and L.V.Egorova

173

Atmospheric Observations at Dome C, Antarctic Plateau, One of the Coldest Place in the World S. Argentini and I. Pietroni

199

Impact of Individual Responsibility in Changing Global Warming? Nitosh Kumar Brahma

221

Navigation with Global Positioning System in Antarctic Circle Rajesh Tiwari 1 , Smita Tiwari 1, P. K. Purohit 2 and A. K. Gwal 3

233

249

FOREWORD The Indian Antarctic program started in the year 1981-82 and soon it was realized that Antarctica holds strongly coupled ice-air-ocean interactive system in the world. Dr. Ram Manohar Lohia Avadh University had an opportunity to participate in four Indian Scientific Expeditions to Antarctica in collaboration with the National Physical Laboratory, New Delhi. I am happy to see the results from the various Indian Antarctic expeditions being poured in the form of a book, which deals with a complex subject of ice-air-ocean interaction over the icy continent. I am also happy to note that there are contributions from Italian and Russian Antarctic stations supporting the SCAR spirit. Antarctica holds the most efficiently coupled ice-air-ocean interaction system which has led to many unique natural phenomena both over the Southern Ocean and over the Antarctic continent itself. In fact, it is the efficient coupling in Antarctica that would help it to maintain and sustain the much debated global change in various ways. I am sure; the book will fill up the gap of scientific results particularly from the east Antarctic regions and the understanding on the ice-air-ocean interactive processes over the Antarctic continent and would inspire the younger generation to formulate their projects for future expeditions to Antarctica from the world over. As an academician, I compliment the authors (Dr. Jaswant Singh & Dr. H.N. Dutta) and all the Authors of various chapters for integrating their knowledge for the advancement of Antarctic science & technology. I wish authors would continue their efforts in future in elevating Antarctic research for the benefit of humanity, which is facing multiplicity of complex problems at the global level. (Prof. R.C. Saraswat)

PREFACE Antarctica is the coldest, windiest, driest and the shiniest continent on Earth, which is surrounded by the stormiest and biologically the most productive oceans in the world. To a first time visitor, Antarctica is seen like a fantasyland and an ivory vastness bisected by ethereal mountains. In addition, this place contains many scientific mysteries like aurora, polar shadows, mirage, katabatic winds, severe cyclones, ozone hole and many other geophysical phenomena. The continent covers an area of 14x106 km which is about 10% of the land surface on earth. Antarctica holds a pristine environment and the world's largest stock of fresh water in the form of a frozen thick ice sheet. Antarctica pushes ice, cold fresh water and cold air mass from its interior towards the Southern Ocean in order to maintain cool around it and to lead many atmospheric/oceanic processes. But the ocean around Antarctica transports back only the air laden with rich water vapor and some minor constituents present in the air. The water vapor condenses to cause snowfall both over the Antarctic continent and over the ocean itself. The snowfall not only maintains the equilibrium for Antarctica to retain its physical strength and shape, it is absolutely necessary to maintain pristine environment. Antarctic environment is the least polluted and is having the highest atmospheric visibility. Antarctica is a magnificent display of interaction between air and the various phases of water in a pristine environment. This interaction has led to the formation of many unique features and many scientific mysteries, which are yet to be explored. Antarctica is now emerging as an important key in the understanding of global environmental concerns. Its unique features have provided scientists with special opportunities to investigate the origin of the continents, the pollution of the globe, ozone hole and changes in world climate. Lack of scientific data remains a major problem for researchers in many areas of Antarctic science; it is basically due to vast size of the continent, inhospitable conditions and the logistic support to sustain the efforts. The contributors are eminent scientists, expedition members and technologists, who have directly experienced the vastness of this continent to realize the Mother Nature‘s craftsmanship in carving the most efficiently, coupled system of ice-air-ocean in the world. The book shall be useful to almost all the planners and researchers working in the area of Antarctic science and technology as it encompasses chapters specifically devoted to Antarctic science, land-ocean-ice-air interaction, influence of solar wind on atmospheric processes, atmospheric observation at Dome C, navigation with global positioning system in

x

Preface

Antarctic circle, effects of UV-B radiations on terrestrial ecosystem, Antarctic lichen and mosses and adaptations of Antarctic flora to survive under extreme environmental conditions. Advances made in recent years have been provided in this book which will be helpful in understanding of Antarctic climate and environmental changes. The book provides up-to-date information on Antarctic ice-air-ocean environment. It is hoped that the book shall benefit the polar scientific community in general and shall stimulate further advancement in the polar science.

ABOUT THE EDITORS

Dr. Jaswant Singh, Associate Professor at the Department of Environmental Sciences of Dr. R.M.L. Avadh University, Faizabad U.P., India and having twenty years of active research career. He has been engaged in teaching to postgraduate students and research on current issues of environmental pollution and management. He has successfully completed six major research projects in the capacity of Principal investigator and edited a book ―Natural Resource management and conservation‖. Currently working on the effects of UV-B radiations on Antarctic cryptrogams and their adaptive strategies to survive under harsh environmental conditions. He has participated in the 22nd and 24th Indian scientific expedition to Antarctica.

Dr. H. N. Dutta is leading Roorkee Engineering & Management Technology Institute, Shamli as Director (R&D) promoting Antarctic research. Prior to this assignment, he served at the National Physical Laboratory, New Delhi from 1976 to 2007, where he worked as the Convener of CSIR Steering Committee on Antarctic Research and led a group on PBL studies over Antarctica. He himself participated in three Indian Scientific Expeditions to Antarctica and carried out multidisciplinary investigations over the Schirmacher Oasis, where India has established its Maitri station. As part of the Indian Antarctic program, Dr. Dutta designed, developed and established a monostatic acoustic sounder at the Maitri station and later on, he became the first in the world to establish shipborne acoustic sounders onboard various ships probing PBL over east Antarctic Ocean. As part of these studies, Dr. Dutta has many unique distinctions to his credit-technology transfer of Antarctic acoustic sounder to a private company for its production, utilizing Antarctic data for taking an international patent, publishing papers in refereed journals and producing several PhD‘s on the Antarctic environment. Dr. Dutta has received many distinctions and honors for his scientific and technological contributions.

CONTRIBUTORS Anand K. Dubey Department of Environmental Sciences, Dr. R.M.L. Avadh University, Faizabad224001, U.P., India. Prof. A. K. Gwal Space Science Laboratory, Department of Physics, Barkatullah University, Bhopal 462026, India. Dr. Dalip K. Upreti Lichenology Laboratory, National Botanical Research Institute, Rana Pratap Marg, Lucknow – 226001, U.P., India. Prof. Dipl.-Ing. Nitosh Kumar Brahma Department of Chemical Engineering, Indian Institute of Technology, Kharagpur721302, W.Bengal, India. Dr. H. N. Dutta Shri Balwant Institute of Technology, Sonepat-131001, India. Dr. I. Pietroni ISAC-CNR via del Fosso del Cavaliere, 100, 00133 Roma, Italy. Dr. Jaswant Singh Department of Environmental Sciences, Dr. R.M.L. Avadh University, Faizabad-224001, U.P. India. Dr. Khwairakpam Gajananda Department of Environmental Science, Faculty of Science, Addis Ababa University,P.O. Box 1176,Addis Ababa, Ethiopia Dr. L. V. Egorova Arctic and Antarctic Research Institute, St. Petersburg, 199397, Russia.

xiv

Contributors Dr. Laxmi Bishnoi, Government Girl's P. G. College, Gurgaon-122 001, India. Dr. N.C. Deb Indian Statistical Institute, 203 B.T. Road, Kolkata-700 108, India. Dr. O. A. Troshichev Arctic and Antarctic Research Institute, St. Petersburg, 199397, Russia. Dr. Pawan K. Sharma Department of Chemistry, Kurukshetra University, Kurukshetra-132 119, India. Dr. P. K. Purohit National Institute of Technical Teachers Training and Research, Shamla Hills, Bhopal462026, India. Dr. Rajesh Tiwari Electrical, Electronics and Computer Engineering Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK. Rudra P. Singh Department of Environmental Sciences, Dr. R.M.L. Avadh University, Faizabad224001, India. Dr. Ruchi Singh Plant Physiology Laboratory, National Botanical Research Institute, Rana Pratap Marg, Lucknow – 226001, U.P., India. Sanghdeep Gautam Department of Environmental Sciences, Dr. R.M.L. Avadh University, Faizabad224001, India. Dr. Sanjeeva Nayaka Lichenology Laboratory, National Botanical Research Institute, Rana Pratap Marg, Lucknow – 226001, U.P., India.

Dr. Smita Tiwari Electrical, Electronics and Computer Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK. Dr. S. Argentini ISAC-CNR via del Fosso del Cavaliere, 100, 00133 Roma, Italy.

Contributors

xv

Dr. Soumi Bhattacharya Space Science Laboratory Department of Physics, Barkatullah University, Bhopal462026, India. Dr. Victor E Lagun Arctic and Antarctic Research Institute, St. Petersburg-199397, Russia. Dr. V. Ya. Vovk Arctic and Antarctic Research Institute, St. Petersburg, 199397, Russia.

ACKNOWLEDGMENTS On behalf of all the authors, the editors are thankful to the National Centre for Antarctic and Ocean Research, Goa (Ministry of Earth Sciences, Government of India, New Delhi) for providing us an opportunity to participate in various Indian Scientific Expeditions to Antarctica. These endeavors have given us a personal experience to bring before the world a volume of scientific work for a better understanding of the ice-ocean-air interactions over Antarctica. The editors would also like to express their sincere thanks to the authorities of the National Physical Laboratory, (Council of Scientific and Industrial Research, New Delhi) and Dr. R.M.L. Avadh University, Faizabad, U.P. for wholeheartedly supporting the Indian Antarctic program and our personal participation. The editors would like to express thanks all the authors who have provided their scientific contributions in the form of various chapters. The views expressed in this book are solely of authors and are not to be attributed to their respective governments and institutions. In this series of acknowledgements, we sincerely express gratefulness to our families for their moral and emotional support while the work was being carried out over the icy continent. The editors particularly wish to thank Nova Science Publishers, Inc. and their staff members for their collective efforts in finalizing and publishing this book. At the end, we would definitely like to thank our readers and we are sure, there might be many shortcomings but we will be very happy to receive suggestions and the criticism to improve ourselves.

Editors

In: Antarctica: The Most Interactive Ice-Air-Ocean Environment ISBN: 978-1-61122-815-1 Editors: Jaswant Singh, H.N. Dutta © 2011 Nova Science Publishers, Inc.

Chapter 1

ANTARCTICA: CONTINENT DEDICATED TO SCIENCE P.K. Purohit 1 *, Soumi Bhattacharya2 and A.K. Gwal2 ABSTRACT Antarctica is a land of extremes: it is the highest, driest, coldest, windiest continent. It is the last continent to be explored and exploited. The continent is known to have many unusual, interesting and unexplored features. Antarctica is not only a place of curiosity for scientist but is a place of interest to layman also. In many ways Antarctica is a ―Scientist Paradise‖. Science is the principal human activity in Antarctica. Being away from polluted places and human interference, unique physical properties, geographical locations, easy for analysis of radio waves, effect of solar radiation‘s, Global warming, effect of magnetic flux on poles, excess of charged particles and ionized gasses in the environment above poles makes it an important place for research. Polar atmospheric conditions affects the atmosphere of the whole earth and provides important information to world related to weather and environment. It is a pristine laboratory and its ice core archives climate history of the past. The unique nature of the region provides a living laboratory where scientists can measure the effects of changes in the environment and climate change.

Keywords: Antarctica, Blizzard, Continent, Earth History, Scientists Paradise.

*

E-mail: [email protected], Fax and Phone Numbers +91-755-2661600 National Institute of Technical Teachers‘ Training And Research, Shamla Hills, Bhopal-462026, India 2 Space Science Laboratory, Department of Physics, Barkatullah University, Bhopal-462026, India

1

2

P.K. Purohit, Soumi Bhattacharya and A.K. Gwal

INTRODUCTION The universe has seven continents namely Asia, Africa, North America, South America, Antarctica, Europe and Australia. Among all continents on the basis of shape and size Antarctica occupies the fifth place. Antarctica is the remotest, isolated and frozen continent of the Earth, with a very inhospitable terrain and a very harsh climate. Antarctica is arguably the most untouched region on the planet that makes it one of the world's most important places to do scientific research. Prolonged stay and research on this continent is fraught with dangers. Antarctica being called as the heaven for scientist and has several unsolved mysteries concealed within it. It is a universally accepted fact that this is the largest pollution free research lab available to the mankind. Antarctica occupies an area between South Pole and Antarctic Circle from 65S and 90S. Antarctic convergence zone lies southward from 50 south and comprises of all islands presents beyond 50 but the actual zone is beyond 66.5 south. This island is banked by water on all sides being Atlantic Ocean, Pacific Ocean and Indian Ocean. Being the highest, coldest, driest, windiest continent it is engulfed by ice to almost 97.6 % and the rest 2.4% part of this continent comprises of iceless part of land. Almost forming one- tenth part of the earth and its area is 14million sq. km. The features of suspense and thrill possessed by this continent fascinate the world. Antarctica is also known as the land of midnight sun, most unbearable weather, house of hail and snowstorms, land of the penguins, a frozen desert, fascinating continent and South Pole with all its attractive features attracts one and all.

Figure1. Map depicting geographical position of Antarctica.

Antarctica: Continent Dedicated to Science

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Figure 2. Mountain of ice in Antarctica.

Two hundred million years ago Antarctica was joined with Africa, Australia, India, New Zealand and South America forming the super continent- Gondwanaland. Forces within the Earth affecting the crust caused these continents to separate and drift apart. Thirty million years ago the continents as we know them today, reached their approximate present positions. Humans didn't even catch a glimpse of Antarctica until 250 years ago. And only in the last 90 years have people begun to explore this vast polar desert in earnest. After conquering the South Pole and the discovery of Antarctica this land happens to be the centre of interest for the scientists to quench their aspirations, and this land no longer remained lonesome. Initially Antarctica was not a frozen land around 70 million years ago and the environment was as similar to other warm islands. There were flora and fauna on the land. But little is known about it today. A new scientific era has already begun with the discovery of Antarctica. India has been sending scientific expeditions to Antarctica every year since 1981-82, and has collected a wealth of data in various areas of science. With the establishment of Dakshin Gangotri in 1983-84 and Maitri in 1988-89, India is now directly involved in polar research.

WHAT IS ALL HIDDEN IN ANTARCTICA? It is very difficult to find out the different minerals that lie under the thick layer of ice, covering the continent. From the samples obtained from mountains it can be enlisted that Antarctica has almost all the minerals that are present in South Africa and South America. On the analysis of the core of land there are chances of iron oxide and coal being present in large quantities. Several other minerals are present there but in very small proportions having very low commercial value. A decade earlier it was decided by the members of the Antarctic treaty that for the coming fifty years the mineral ores comprising of hydrocarbons, oil and gas would not be extracted from here. But the water from the glacier could be utilized. It is believed that in the future we would be able to find more deposits of oil and natural gas. The extremely cold temperature of the continent, the thick layer of ice being harder than iron, being very far from other continents, the problem due to transportation, to cross the enraged and frothy oceans, big glaciers, the split of ice shelf forming icebergs that flow in the ocean, the water of ocean being frozen, the icebergs which can collide and break the ships to pieces, all these act as obstacles to the natural extractions of these minerals.

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The fossils of the past atmospheric inhabitants lie in the layers of ice. Due to excess of ice the plant samples are well protected waiting to be unearthed. Antarctica is a vital area of attraction not only due to its scientific value but also due to its geopolitical and commercial values. Its comprises of valuable minerals like copper, gold, zinc, manganese, tin, uranium various gases and oil. But the mining of minerals and commercial usage are not allowed at present. The water bodies have species that may possess some commercial usage. Nature has bestowed on the Antarctica some ornamental and natural blessing, which are of prime importance due to their geographical and scientific values. It is very surprising to enlist that the ice of Antarctica holds about 90% of pure water of the world. Several such icebergs melt here every year. Scientists are making an analysis of expenditure regarding transportation of these icebergs by huge ships to fulfill the requirements of drinking water. A single small iceberg has the potential to fulfill the water requirement of a metro town in prime countries. An iceberg that broke form this continent in 1963 is perhaps the largest ever known iceberg with a length of 335 kms and width being 97 kms. It floated for 12 years before losing its existence. In the interior regions extremely low temperatures, several months of complete darkness, fierce winds and blowing snow combine to make life virtually impossible. Antarctica is the harshest in the world. Wind chills freeze exposed skin in seconds; blizzards can reduce visibility to a few feet, months of darkness and seemingly endless expanses of snow and ice. Most of Antarctica is covered with vast areas of snow and ice, which reflect about 75% of the incoming solar radiation.

THE FASCINATING CONTINENT The human interest in Antarctica has been to compute the origin of scientific inquisitiveness occurring here. Initially the inquisitiveness was limited only up to finding the geographical locations. As far as possible the initial expedition‘s team has tried to gather samples and data regarding weather, flora and fauna. Several deep secrets of nature are enclosed in the continent. As a challenge to science this place is a fort of unsolved mysteries. The continent being free form pollution and being called as world‘s largest laboratory why does it captivate the scientists of the world? Being away from polluted places, unique physical properties, geographical locations, easy for analysis of radio waves, effect of solar radiation‘s, effect of magnetic flux on poles, excess of charged particles and ionized gasses in the environment above poles makes it an important place for research. Solar radiations and the highly energetic charged particles having ionization power present in the upper atmosphere are responsible for magnetic storms and form aurora affecting the transmission of radio waves. These entire phenomenons can be studied here very well and in fact scientists are undertaking these studies in greater detail. Polar atmospheric conditions affects the atmosphere of the whole earth and provides important information to world related to weather and environment. During winter nights, at the time of absence of solar radiations and absence of direct ionization is a special property of Polar Regions. This continent offers a golden chance of analyzing effects of geo-magnetism on structure and mechanism of ionosphere. During


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summer season when Antarctica has continues day for few months that causes ionization at a constant rate in the upper atmosphere due to solar radiations and excessive heat. A regular measurement of geo-magnetic activities at the permanent research centers of all the nations is being carried out. The data records pertaining to this is being properly analyzed and utilized for navigation purposes. Information can be obtained regarding the movement of magnetic poles. One can perform a complete analysis related to these phenomena‘s and it could be utilized for social welfare. North and south poles are maintaining the energy balance of the world. The energy from atmosphere and oceans coming to the poles loses its identity and converts to thermal radiations. The cold winds in this region combines with hot air of lower latitudes to form clouds thereby regulating the global environment. To predict the changes in atmosphere in the future it is necessary to analyze the trend in the past. This continent is ideal for such types of analysis. The ice that has been accumulating from years withholds natural secrets amongst its layers. Antarctica is a ―Scientists Paradise‖. Science is the Principle human activity in Antarctica. It is a pristine laboratory and its ice core archives climate history of the past. The unique nature of the region provides a living laboratory where scientists can measure the effects of changes in the environment. Ongoing research is crucial to the understanding and monitoring of the global warming, ozone depletion and atmospheric pollution. The important research work associated with this place is the discovery of ozone hole, gradual increase in temperature of Earth, information regarding presence of antifreeze chemical in the body of fishes. Atmospheric research is one of the areas for which Antarctica provides a rich ground. The fundamental knowledge gained here is currently being used for practical applications and has potential promise for future applications as well. Antarctic ecosystems are ideal for biological research due to many factors. Few life forms survive above the ice because of harsh environmental conditions. A simple, land-based ecosystem is easier to study here. Thick Antarctic ice sheets provide one of the best records for past climate change. Ice cores can reveal patterns of mean air temperature, evidence of major volcanic eruptions and composition of the atmosphere. Antarctica and the surrounding areas are natural laboratories for scientific research that cannot be done anywhere else on Earth. Geophysicists can take advantage of Antarctica's ideal conditions to study the effects of solar radiation on the Earth's magnetic field. The geographical location of Antarctica has been a field of special interest for the Indian scientists. Pacific and Atlantic Ocean meet both the poles of earth but Indian Ocean has land in the north and Antarctic Ocean in the south. Indian Ocean captures the enormous energy available here and carries it across to the country. This continent is called as key of the weather of the world. Information regarding weather, climate and water can be obtained from this continent. Because of its geographical location it‘s the best and static location for atmospheric researches. Scientists pertaining to geography and environmental study have accepted this as their prime research area. This land is primarily useful for researches pertaining to pure and applied science areas.

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Figure 3. Scientists taking metrological observations and UVB measurements.

IDEAL PLACE FOR SCIENTIFIC INVENTIONS Antarctica is a land of extremes yet these extremes offer spectacle and beauty. It is the last continent to be explored and exploited – the continent about which still least is known has many unusual, interesting and beautiful features. The scientists of various nations working in Antarctica undertake in depth research and measures ozone, ultraviolet radiations, carbon dioxide, carbon monoxide and Green house gases. In our atmosphere at a height of 30 to 50 km ozone layer is present. This layer protects life on earth by preventing harmful UV radiations of sun and upper atmosphere to reach earth surface. In the beginning of the century people could not imagine that this gas only being 0.03% is responsible to maintain the environmental balance and probably this unawareness has been the reason for ozone depletion. During the period of 1969 to 1989 a fall in ozone by 3% was observed. In the year 1985, British Antarctic survey scientist J. Farman declared a startling and disturbing discovery, ozone levels in the stratosphere over the South Pole were dropping precipitously during September and October every year as the sun reappears at the end of long polar winter. This ozone depletion phenomenon has been occurring at least since 1960s but was not recognized because earlier researchers programmed their instruments to ignore changes in


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ozone levels that were presumed to be erroneous. It was also informed that in 1970 the thickness of this layer was almost double than is 1981 and the rate of ozone depletion had picked up pace. The exceptionally cold temperatures in Antarctica play a role in ozone losses. The cooled air gets settled on the poles because of which chlorine gets accumulated on troposphere. During summer season at Antarctica the sun is present for all 24 hours. The reaction of chlorine and ozone continue to occur all the time in presence of sunlight. This depletes the ozone layer. During September and October the hole widens to cover the whole of Antarctica and southern Australia. Hole in ozone layer has been observed on North Pole also. Springtime ozone hole in Antarctica provides favorable atmospheric conditions for observing the celestial dome. This window enables scientists to probe the structure of the Sun and the universe with novel precision. Evidence for levels of global pollution by industry, agriculture and transport sectors is frozen into the Antarctic ice. Antarctic 4.75 km thick ice sheet is a record of past climate for the last 5,00,000 years. Antarctica is a vital area of attraction not only due to its scientific value but also due to its geopolitical and commercial values. The winter season here is from April to September and summers are from October to March. In the winter season this continent doubles itself as the ocean around these freezes. As it occupies positions on the pole hence it has nearly six months of darkness and six months of day. Indian station Maitri located on Shrimachar Mountain has day from 22nd November to 24th January and continuous night from 31st May to 20th July. This continent is hit by most severe adversity of climate. The minimum temperature recorded here is -89.2C at the Vostok centre of Russia in 1983. The wind velocity and velocity of storms recorded here has been 320 km/h. The windstorms and hailstorms continue for days together. Calamities like breaking of ice, breaking of ice shelf, formation of icebergs and its flow into the waters for Kms together, formations of rifts in ice, render an utmost challenging and almost impossible working environment to people engaged in researches here. The reflection of sunrays due to ice almost renders the researchers to continue their work and increases the chances of getting lost. Antarctic can be compared to a desert also. Any area of land that has less than 254 mm (10 inches) rain than it is called as desert. There is almost no rainfall here even if rain falls it is in the form of snow. Hence it‘s called as a cold desert. During winter season the area of sea ice increases to 20 million sq. kms, which is larger than the total area of the continent. Every year almost 85% of this part melts in the summer seasons. The whole game is of the weather; even a smallest flaw in understanding the climate can turn disastrous. There must be a thousand mysteries that lie unsolved in Antarctica. The more mysteries that are unfolded the more hidden mysteries line up. There are countless mysteries in Antarctica being almost impossible to count. It is strange but a fact that Antarctica plays a vital role in the weather and climate mechanism of the whole earth. A key role is played by Polar Regions in regulating the climate of the world. To derive facts and figures related to such issues an in-depth analysis of the climatic mechanism at Antarctica has to be done. About 97.6% of ice of this continent inclusive of the oceanic ice is very sensitive towards the global warming. The ice holds enormous reserve of water inside it. The risk of increase in sea level may arise by melting of this ice. The whole coastal region is surrounded by winds hence sudden changes of weather

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are natural. The climate of this place is considered to be the most hazardous amongst all continents. The strong winds due to gravitation give birth to storms, which flow from lower regions of the continent to upper regions. Keeping the diversity and importance of the weather and climate of this region January Ist, 1957-58 was celebrated as International geophysical year. Along with these celebrations all the nations started the race of exploration of this quiet Zone. A non-governmental organization named SCAR (Scientific committee on Antarctic Research) was set up in 1958. The committee acts as a regulator for nations doing research here and also establishes co-operation between these nations. A new avenue was opened in the field of Metrology in Antarctica after establishment of IGY and SCAR. Antarctica has day for 24 hours in summer and 24 hours of night in winter. We know that the earth revolves around the sun and simultaneously rotates on its axis also. The earth is tilted 23½ on its axis. During revolution half of the earth that faces sun has day and the other half portion that lies in the dark has night. Antarctica lies on the south pole of the Earth and when there is day on the North Pole the South Pole has complete night. The Earth‘s South and North Pole plays an important role in research of global weather and climate because heat from lower latitudes is transported to high latitudes through meteorological process and is than radiated from polar latitudes at larger wavelengths. Analysis of meteorological data‘s collected here is of paramount importance in modeling of global weather and climate. The weather of Antarctica is made up of uncertainties, nonconsistencies and hindrances. There is no similarity and balance in the climatic factors here. Many nations have set up static or permanents centers in the white continent and have established their laboratories regarding weather and climate. The environmentalists here conduct research on weather related factors of this place. Antarctica affects the atmospheric and oceanic cycle inside the southern hemisphere hence has an impact on the atmosphere and weather of the world. The ice here acts as a heat absorber, thereby regulates the sea level. To know the environment of the world completely it‘s essential to know about energy balance of this white continent. This frozen ice has detained mysteries of climate of past several thousands year. To calculate weather of a particular place the data of surroundings is essential. To predict weather of an area the data both of the surface and upper atmosphere of various regions is required. There are huge uninhabited areas as well as a major area is occupied by water hence the complete zone cannot be inspected and no related data‘s can be obtained. The various weather satellites set up by several nations have achieved laurels in the area of weather predictions. To give exact prediction of weather this place is only partially suitable. The climate here depends on the weather of the sea, which is devoid of any static laboratories. The ice of Antarctica is a key factor of the weather mechanism of earth. The whole continent is surrounded by ice, which spreads to 18 million sq. kms during winters and melts to two sq. kms during the summer season. The ice is quiet sensitive to these changes of weather. To collect figures and samples from this ice covered regions is difficult and hazardous but has been eased by remote sensing. From time to time scientists were able to extract huge ice cores to analyze the life structures and climate of the past. This would help in knowing the changes of the atmosphere


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that has undergone in the past. This information is related with changes in temperature, carbon dioxide, ozone level, atmospheric pressure etc. Low pressure group of air move southward from 500 to 700 along with regular wind. At times its a group of 5 to 6 slabs at low pressure which have impact on surrounding of Antarctica move eastward at a speed of 90 km/hour. Cold winds towards the coastal region gives rise to high velocity snowstorms, which may occur for a few hours or several moths altogether. In the early years information was collected to derive normal conditions but now permanent laboratories have been constructed to assist research. Research using hi-tech devices was initiated only in the sixties. International Antarctic Analysis centre was set up to analyze the data available with all the nations collected from work of several years. The data held was also published so that it could be used to unravel mysteries of weather. Later use of satellite was made to predict weather, climate, pressure, temperature, humidity, direction and velocity of wind etc. Correct information of all these factors was available only because of the satellites used. After the use of these technologies it became easy to know about the location of low-pressure area. To know the climatic hazards of this region information for research is being made available through world climate research program and World Meteorological Organization. Today efforts are being made to know the degree to which weather can be predicted and the human activities affects the weather. Some scientists belonging to member nations of SCAR are conducting research pertaining to movement of ice, its thickness, energy flux and activities in the atmosphere. The layer of ice serves as a mirror to solar radiations coming from the top and reflects these rays back into the atmosphere. There by this continent shreds energy in the form of radiations and acts like a global energy sink affects the weather. To know in detail about the weather and climate total devotion and carefulness in required. It is essential requirement to analyze the surroundings of Antarctica and the ocean and also to analyze the reactivity and effect on oceanic waters. Weather experts in various centers have analyzed pieces of ice to know chemical reactions along with freezing and changes in atmosphere several decades before. Russian scientists have analyzed the freezing rate, atmospheric temperature of oxygen, percentage of compounds of hydrocarbon in an ice slab extracted from 2000 mts under ice. With more human intervention for research the carbon dioxide percentage has increased causing an increase in the green house effect due to which an increase in the warmth of the continent is observed. On analysis of pieces of ice from the layer for the gases enclosed a rise in percentage of CO2 has been proved. Two hundred years ago the percentage of CO2 was 200 ppm, which went upto 280 ppm hundred years ago and now it has risen to 340 ppm. Many years ago the reason for low CO2 percentage was dissolution of CO2 in cold water, which has better dissolution capacity than hot water. Thus the glaciers were more static pertaining to low CO2. In the recent years almost all nations have established their automatic weather stations in this region. Implementing the modern hi-tech devices information regarding Antarctic and the rest of the world can be predicted at least a week before. This white continent has become an inseparable part of the climate and weather mechanism of the globe. It is even possible to calculate the weather of high latitudes easily. From the first expedition, India had started gathering information related to weather for research purposes. Regular per minute inspection of the velocity of air, state of clouds, visibility, humidity, vapour etc. by the Indian metrology department is going on. The

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laboratories have all self-start and automatic devices. These laboratories experimenting on diffused solar radiations, surface ozone, total ozone, ultra violet radiation, measurement of Green House Gases etc. The prior prediction of weather is useful especially for scientists who perform research work in the Antarctic fields. The average temperature of Antarctica is - 490C. On the southern pole the sun shines for 24 hours and for nearly 6 months but if one feels that a little warmth can be felt due to sun it is wrong. The outside world avails information regarding Antarctic from data‘s available through satellite. Satellite can be used to obtain information regarding temperature of water, ice layer on water, construction and expansion of ozone layer. The recording of the climate of this region started in 1950. Through the data and pictures available from satellite the state of clouds, velocity and movement of storms, formation of ice and its distribution and various environmental processes can be updated. Various global climatic models clearly indicate that there would be enormous changes in the climate of Antarctica during the next 100 years which would cause an increase in temperature that would in turn increase the snow melt. The available climatic models have failed to produce reliable data of the changes in weather hence more research is required in this field. Several experiments have proved that there are certain changes occurring in the upper atmosphere. In ionosphere in the F- region (300 kms) the peak of concentration of electron density from the past 38 years has come down by 8 kms. In the lower atmosphere due to increase in concentration of green house gases the temperature has increased but the upper atmosphere has become relatively colder. The various theoretical analyses have shown that the layers have decreased. Southern ocean acts like a sink in global carbon cycle. The layers of ice, oceanic ice and oceans are active factors of climate. The polar plates being formed over Antarctica render it coolest. There is extreme cold due to flow of cold air. The air flows from cold mountains at a height of 9000 feet downwards and flows towards the coastal region. The rotation of earth deflects the air to left side. Researchers believe that these cold winds have major effects up to long distances. In the coastal areas the wind velocity is 150 meters per hour. The 5 meter thick ice of this continent deposited from 5 lakhs years encloses the climate of the past. These gas bubbles enclosed in the ice are a witness of pollution caused by environmental gases, industrialization, atomic bomb and fertilizers used for crops. The future climate and weather can be predicted on the basis of research on theses factors. Every year during winters about 7 million sq. kms of ice deposits around Antarctica, which melts during summers. This is the biggest event associated with weather. Scientists have discovered two more sub glacial lakes, raising renewed speculation of the existence of living ecosystems below the ice. The one lake is called "90°E" because it lies along that longitude and is now the second biggest sub glacial lake in Antarctica, while the other is named after the Russian station above the lake called Sovetskaya. These lakes were known of before but this is the first time that scientists have been able to assess their size using satellites and ground penetrating radar equipment. Scientists and experts coming to Antarctica are conducting research on various problems. Zoologists are analyzing the behavior of animals residing here and are trying to find out reasons due to which they can survive in this hostile environment. Some scientist has discovered very small plants growing inside rocks. The biologist‘s analyzes water of lakes covered to find out fecal coli form and other chemical contaminations. Environmental and weather experts analyze the climate of Antarctica and trying to discover reasons of the


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alterations regarding the unpredictability of weather. Geologists are performing critical analysis of the rocks and mountains ranges to find out the history of earth. They have been very successful in discovering minerals and ores. Glaciologists have analyzed the Antarctic ice and have gathered ice samples. Physicists have done research on southern magnetic poles and wind. They have gathered vital information regarding the ozone layer and its depletion. For Astrologist this area is matchless as during summers the sunlight is available for days together.

LIFE IN EXTREME ENVIRONMENT Although it seems quite unbelievable that even under such adverse climatic conditions life is possible but this fact is absolutely true. The Antarctic continent where earlier human settlement was beyond imagination is now a home to numerous permanent bases where the scientists conduct research and experiments throughout the year. In spite of the dangerous weather and hostile environmental conditions plants survive here. Almost 350 species of plants are found here all of which represent lichen, algae and moss. The natural flora and fauna does not have a big influence on the environment. The continent has absence of higher order plants. The higher order plants refer to those that markedly exhibit flowers, leaves, root system and fruits. The research regarding the vegetation of this place started after 1960. This was done after the predominant plants of this region were collected in large numbers as samples and were grouped into species to do a selective analysis. Many important conclusions were drawn after studying the plant density, life cycle, behavior and chemical characteristics. The outstanding feature of analysis was how the plants have sustained the adverse conditions and survived. These plants being green are producers prepare food through the process of photosynthesis for consumers. In the barren valleys of Antarctica a few rocks are found which leave space for air and moisture within them. Some of these rocks being translucent allow light to penetrate as a result some primitive type of vegetation is able to grow and survive. The namesake greenery is due to green colored ground algae, during summers this alga shows a little growth. The cold temperature and snow cover during winters curb the growth of these algae. The prevailing darkness during winters does not allow the photosynthesis to take place. In the Antarctic Peninsula some green grass can be spotted, as the temperature of this region is little warmer. Here as compared to marine life forms the terrestrial life forms are in great minority. This plays a vital role in the Antarctic food chain. During the summer season due to longer days it shows tremendous growth in the water under the floating ice. Marine microorganisms consume this. The microorganisms are intern consumed by krill and other small fishes. Lichens are abundantly growing on bare rocks and display different colors such as orange, dark brown, black etc. Their rate of growth is very slow almost being approximately 1cm in a century. These can survive in dry and passive region for long periods and are able to perform photosynthesis at even very low temperature at – 200C also. Creatures found on this continent comprises of seals, whales, penguins, krill, petrel, skua, mite‘s etc. All activities within the Antarctica continent and the waters around it are regulated and governed by a unique treaty called ―Antarctic Treaty.‖ The need of this treaty was felt to

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provide a constituted outlook to the research happening here so that it could benefit all nations.

WHO OWNS ANTARCTICA? All activities within the Antarctic continent and the waters around it are regulated and governed by a unique treaty called ―Antarctic Treaty.‖ The need of this treaty was felt to provide a constituted outlook to the research happening here so that it could benefit all nations. The Antarctic treaty was made on December 1, 1959 but was enforced on June 23, 1961. Antarctica is an international conservation and research area managed by a group of countries all of which are signatories to the Antarctic Treaty. Hence no individual, organization or country owns Antarctica. The scientists working here on environmental conservation issues are given full freedom. The scientists came here through their national research programmes but the tourists who visit this place are also given a guideline, which they have to follow. For years to come Antarctica would remain a fabulous place for the tourist and a challenge to the scientific community. Antarctic research may be a long way from home, but it is an outstanding and most pertinent in present day context of Global warming and climate change.

REFERENCES Chaturvedi, A:. Rochak avam Romanchak Antarctica: Prabhat Prakashan, Delhi, pp.1-256, ISBN No.81-7315-532-1, (2006). Khare, N.: Dharkta Mahadeep, NCAOR, Goa (2000). Girija R.:-Atmospheric research from Antarctica, the Indian contribution, pp. 1-104, IIG Bombay (1993). Purohit, P.K.: Antarctic: Vigyan Avam Chunotion., Madhya Pradesh Hindi Granth Acadamy Bhopal, pp. 1-116,(2004). Purohit, P.K.: Antarctic: Aakarshan Kyon? Indira Publishing House Bhopal, pp.1-175, ISSN No.818910703-8, (2005). Purohit, P.K.: Antarctic: Where the Silence Speaks, Indira Publishing House Bhopal, pp. 1180, ISSN No. 8189107-14-3 (2006).


Chapter 2

AN INSIGHT INTO THE OCEAN-ICE-AIR INTERACTIONS OVER THE EAST ANTARCTIC MARINE BOUNDARY LAYER: UNIQUE PHENOMENA H. N. Dutta1 *, Pawan K. Sharma2, N.C. Deb3 and Laxmi Bishnoi4 ABSTRACT Antarctica is a magnificent display of interaction between air and the various phases of water in a pristine environment. This interaction has led to the formation of many unique features over the Antarctic continent, which is surrounded by an equally magnificent ocean known as the Southern Ocean. India‘s interaction with the Southern Ocean effectively started with the launch of Indian Scientific Expeditions to Antarctica in the year 1991 and as part of these expeditions, India made several attempts to install various types of shipborne acoustic sounders onboard various ships, which were part of these expeditions. The present Chapter deals with the understanding of the marine boundary layer over the east Antarctic region as probed by a shipborne acoustic sounder installed onboard the ship Megdalena Oldendroff, which sailed to Antarctica as part of the 21 st Indian Scientific Expedition in the year 2002 from South Africa to Antarctica. In the entire period from 22 January –March 3, 2002, which is of 984 hours in terms of duration, the system recorded data only for 476 hours, which is 48.37% and the rest of the data contained windy conditions, system maintenance etc. Even with this limited data, it is clear that most of the time, the marine boundary layer remains stable and the thickness of the ground based inversion was about 150 m although its ranged varied between 50-325 m. Similarly, in the case of thermal convection, the plume rise has recorded variability between 100-450m and most of the plumes reached up to a height of 300 m. *

E-mail: [email protected] Roorkee Engineering and Management Technology Institute, Shamli-247774, U.P. India 2 Pawan K. Sharma, Department of Chemistry, Kurukshetra University, Kurukshetra-132 119, India 3 N.C. Deb, Indian Statistical Institute, 203 B.T. Road, Kolkata-700 108, India 4 Laxmi Bishnoi, Government Girl's P.G.College, Gurgaon-122 001, India 1

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H. N. Dutta, Pawan K. Sharma, N.C. Deb et al.

Keywords: Acoustic sounder, Marine boundary layer, Shipborne, Southern Ocean.

1. INTRODUCTION Antarctica is a magnificent display of interaction between air and the various phases of water (vapor, liquid and solid) in a pristine atmosphere, where the direct solar energy reaches the Pole for six months of the year at very low elevation angle, and for the other six months of the year, it is dark. This has already led to the formation of a dome shaped, permanent ice cap, which is about 4 km thick in the interior of the continent, having an area of about 14.5 m km2 (or a circle with a radius of about 2000 km). Antarctica is surrounded from all around by an equally magnificent ocean called as the Southern Ocean and both the Antarctic continent and its surrounding ocean are connected through the most efficiently coupled ocean-ice-air system (Bailey, 2000; Schellenberg et al., 2002; Liu et al., 2004; Hall and Visbeck, 2002; Parkinson, 2004; Simmonds and King, 2004; Naithani, 1995). The Southern Ocean is dominated by a yearly variation of sea ice; its maximum area is about 19 million km2 in late winter and the minimum about 4 million km2 during late summer (Arrigo and Thomas, 2004). The moment sea ice forms, it reflects the solar radiation, thus enhances the sea ice growth. Also, being a poor conductor of heat (Van den Broeke et al., 2006; Lefebvre and Goosse, 2008), it separates the warm ocean water and the colder atmosphere and thus stops the transfer of heat from ocean to atmosphere and vice versa. Moreover, when sea ice forms, brine is rejected into the underlying ocean creating a layer of saline, dense water decreasing the vertical stability at the base of the oceanic mixed layer (Kwok and Comiso, 2002). Subsequently, entrainment causes a negative feedback between the ocean and sea ice, whereby the deeper, warmer ocean water is brought to the surface, increasing oceanic heat flux and inhibiting sea ice growth (Martinson, 1990; Marsland and Wolff, 1998). The heat flux is greatest initially when brine rejected by the rapidly growing ice sets up thermohaline convection in the underlying water. As the rate of ice growth and brine rejection decreases, so does the convection and the heat flux to the lower ice boundary drops off. During summer, sea ice melts mostly by warming of the ocean mixed layer through heat input (mainly solar radiation) in open water areas (Ohshima and Nihashi, 2005). Also, a large number of low pressure areas in summer result ocean swells and high winds breaking the ice into large pieces that move under the influence of wind and currents. (Fast-ice is sea-ice that is held fast to the continent.) Pack ice can change in a matter of hours from being open and navigable to densely packed and impassible. The large seasonal fluctuation of the sea ice cover affects the exchange of energy, mass and momentum between the ocean and atmosphere, and is extremely important in controlling the existence of Antarctic continent and its interaction with the whole globe (Lefebvre and Goosse, 2005, 2008; Simmonds, 2003; Thattermann and Levermann, 2009; Busalacchi, 2004; Meskhidze and Nenes, 2006; Ito et al., 2010; Ved Parkash, 2008; Liss et al., 2004). The Southern ocean's circulation system has another unique feature known as the Antarctic Circumpolar Current (ACC), which is both the longest and the strongest current in the ocean carrying a volume transport of 130 Sv (1 Sverdrup=1 Sv=1×106 m3 s−1) along a

An Insight into the Ocean-Ice-Air Interactions over the East Antarctic Marine…

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24 000 km path encircling Antarctica (Gille, 1994). The ACC is also unique because no continental barriers exist in the latitudes spanning Drake Passage (the gap between South America and the Antarctic Peninsula), which allows the current to close upon itself in a circumpolar loop and is the primary means of inter-basin exchange of heat, carbon dioxide, chemicals, biology and other tracers. Despite its essential role in the climate system, the ACC remains one of the most poorly understood currents in the ocean (Thompson, 2008). At the same time, deep waters in the Southern Ocean are rich in dissolved inorganic carbon (DIC) and depleted in oxygen. When circulation brings these waters into the mixed layer, the soluble gases are exchanged at the air-sea interface. The formation of deep mixed layers combined with high biological productivity make the Southern Hemisphere extra-tropical oceans an important component of the global carbon cycle (Bishop and Wood, 2009).

2. INTERACTION BETWEEN THE MAIN ANTARCTIC CONTINENT AND THE SOUTHERN OCEAN The interaction between the Southern Ocean and the Antarctic continent (Dierer et al., 2005; van Ommen and Morgan, 2010) has already led Antarctica to be the coldest (due to the thickest dome shaped ice cover on Earth), windiest (again due to thick dome shaped ice cover and by the least polluted pristine environment), driest (due to low temperature, water vapor freezes into ice and whatever is left, it is pushed towards the ocean by the katabatic winds. Also, the katabatic winds make the icy surface harder, as evaporation causes cooling, thus help in maintaining stability of the dome shaped ice) and the least polluted (pristine environment-the frequent snowfall cleans the atmosphere and almost all the particulate matters are pulled down and buried under the ice forever). Also, the pristine environment helps the radiative energy-Infrared/heat energy to escape to the sky without any hindrance, leading to the formation of steep surface based inversions in the lowest atmosphere resting on the icy slopes of Antarctica. This air mass is pulled by the gravity and flows out of the periphery of the continent as the unidirectional, highly consistent winds, called as katabatic winds. These winds trigger / force or create warm-air advection for creating atmospheric cyclones over the ocean, with the result, Antarctica is surrounded all around by the stormiest ocean in the world (Fyfe, 2003; Kalnay et al., 1996; Lin and Simmonds, 2002; Carrasco et al., 2003; Gajananda, 2002). These cyclones, in-turn, pump moisture over the continent, leading to the snowfall (Genthon and Krinner, 2001; Guo et al., 2003; Gajananda et al., 2004, 2007) and churn the oceanic water, creating trillions and trillions of water droplets, thus rendering a perfect turbulent transfer of air into the ocean and the transfer of the oceanic gases, water vapor, pollutants, microorganisms etc. into the air (Gajananda et al., 2004; Gajananda and Dutta, 2005; Lim and Simmonds, 2007; Bargagli, 2008). All these microorganisms, various pollutants, sea salt particles, oceanic gases and water vapor have invaded the periphery of Antarctica and form an important subject of investigations over the ocean and oasis regions of Antarctica (Honjo, 2004; Gajananda et al., 2004, 2007; Kerminen et al., 2000; Ved Parkash, 2008). Antarctic continent and its surrounding ocean are connected with each other basically in four ways:

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H. N. Dutta, Pawan K. Sharma, N.C. Deb et al. 2.1. Ice interaction: The ice from the main continent is slowly pushed towards the ocean due to gravity and a part of this ice breaks in various forms to maintain the cool over the Southern Ocean (Joughin and Tulaczyk, 2002; Ng and Conway, 2004; Rignot, 2006). It is important to note that the Antarctic continent pushes ice into the surrounding ocean, while the ocean creates snowfall over the entire continent and over the ocean itself. 2.2. Water interaction: During local summer, over the main continent, when the upper portion of the ice melts, the water either gets collected in depressions, forming pools/lakes or tries to cut the ice to create trenches, crevasses, tunnels etc. flowing out of the continent towards the periphery. The water gets collected in the form of lakes / ponds etc. over the oasis regions or flows towards the ocean (Naithani, 1995; Gajananda, 2002; Gajananda et al., 2003). The formation of water alters the surface albedo and wherever, water gets collected, it dissolves more and more ice. Also, at the periphery of the continent, the lower portion of the shelf ice gets dissolved in the relatively warm oceanic water (Vaughan and Doake, 1996). In any case, over the past millions of years, there has been a perfect equilibrium between the ice melting during summer and freezing during the winter period. In fact, there should be more deposition of ice during winter than the melting during summer, so that the net balance is positive, but confirmatory results are still awaited (Wingham et al., 2006; Ramillien et al., 2006). 2.3 Air interaction: The third interaction is through the air, which is the lightest form in terms of density and specific heat compared to water and ice. Over the main continent, due to pristine atmosphere, the icy surfaces emit infrared energy to the sky, resulting in the formation of surface based inversion. With the result, the air resting over the icy slopes becomes much heavier than the air aloft, thus it is pulled by the gravity towards the periphery of the continent. As the air move towards the periphery, its velocity increases tremendously and it pushes the lower atmospheric water vapor towards the periphery. This unidirectional moving cold and dry air mass is known as katabatic winds (Kumar, 2002). It is important to note that although the katabatic flow carries very cold and dry air, its remarkable strength may disrupt the surface temperature inversion by vertically mixing the cold surface layer with the upper and warmer atmospheric layers, causing a surface warming (König-Langlo et al., 1998). In addition to this mechanism, also the frictional and adiabatic heating of the katabatic flow may contribute to warming the near-surface air. Over the Southern ocean, the relatively cooler, dry katabatic winds trigger many phenomena, including the formation of sea ice over open ocean areas and pushing it away from the periphery of the continent. Also, the katabatic winds trigger the formation of cyclones over lower latitudes. These cyclones, in turn, lead to snowfall over the continent and the entire loss of ice in various forms gets compensated. The intensity of katabatic winds is more pronounced during local winter, as the cooling of the icy surfaces is the highest. 2.4. Radiation interaction: The snowfall during winter covers almost all the portions of Antarctica, so that in local summer, the Sun rays get reflected as part of the survival strategy of Antarctica and its surrounding (Naithani, 1995; Gajananda, 2002; Pirazzini, 2004). Also, during snowfall periods, the entire atmosphere becomes


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cleaner, as the suspended particulate matter in the air is brought down by the falling snow flakes and buried in the ice (Wang et al., 2008; Boucher et al., 2003; Eisele et al., 2008; Stohl and Sodemann, 2010; Gajananda et al., 2004, 2007). This cleaning of the atmosphere is essential for the radiative part to be efficiently active over the entire Southern Ocean. The cleaning of the atmosphere also happens even during summer, when the cyclones lead to snowfall. This is an absolutely essential component of the entire Southern Ocean environment as for the formation of the sea ice, it is necessary that the radiative energy must escape to sky without any hindrance or modification etc. (Chamberlain et al., 2000; Lawrence et al., 2004; Naithani et al., 1994). In summer, cyclones may also result in some rainfall events at the periphery of the continent (Deb et al., 1999; Ved Parkash, 2008). In fact, over the past thousands of years, the loss of Antarctic ice had been lower than the total amount it gained and that‘s how, Antarctica is holding its physical structure and is participating in the controlling the global temperature and many other important features. Even in the past, there has been no change in the snowfall over the continent since the IGY (Monaghan et al., 2006) and Antarctica seems to be stable in some respect (Gudmundsson and Jenkins, 2009). However, many signals or worries are related to the global warming, which makes the subject of ocean-ice-air interaction to be an important science subject (van de Berg et al., 2006; Justino et al., 2010; Peck, 2005; van den Broeke, 2008; Bindschadler, 2006; Steig et al., 2009; Gille, 2008; Zazulie et al., 2010; Atkinson et al., 2004). In fact, to strengthen our knowledge about various aspects of Antarctica, many programs are in progress (Rignot, 2002; Frey et al., 2009). Once the katabatic winds are forced to blow over the ocean, they move up the relatively warm and humid air. As this humid air moves up, it moves into a region of low pressure and cools. The associated water vapor also cools to form water droplets or directly into snow, releasing latent heat. This release of latent heat creates a low pressure area, with the result; more air is sucked into this region. Thus, it triggers the formation of a well defined or well developed cyclone over the ocean, which has to move towards the continent. The cyclonic air from the ocean side is relatively much warmer than the existing Antarctic air, leading to warming of the atmosphere, which is more noticeable in winter months (Naithani, 1995; Gajananda, 2002). In fact, there are events over Antarctica, wherein a widespread warming has been observed both during local summer and winter seasons (Enomoto et al., 1998; Deb et al., 1999; Van As et al., 2007). In summer, the katabatic winds are weaker but the number of lows per month is higher in summer due to advection of water vapor (Naithani, 1995; Kumar, 2002; Carrasco, 2003; Ved Parkash, 2008). At the same time, the invaded moisture by the cyclones may lead to the formation of fog over the periphery of the continent (Gera et al., 2002; Walden et al., 2003; Gajananda et al., 2003; Gajananada et al., 2007). These cyclones approaching from lower latitudes (moving from west to east), become the main sources of heat for the atmosphere, and the atmosphere-surface heat transfer takes place through turbulent mixing and longwave radiation, the latter is dominated by clouds. The cyclones are also responsible for warming of planetary boundary layer around the periphery of the continent during winter.

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Also, the cyclones replenish the loss of ice in the form of fresh snowfall all over the continent and around the ocean. The freezing ice in winter and the falling snow cover almost all the exposed parts even at the periphery of Antarctica, thus prepare the entire continent to be ready to reflect the falling Sun‘s energy during the local summer. The atmospheric research in Antarctica is increasingly important as many processes taking place in the atmosphere are still barely understood (Anisimov et al., 2007). This is particularly true for exchange of gases and particles between ocean and atmosphere, an area of study which is currently receiving much attention (Meskhidze and Nenes, 2006; Zorn et al., 2008). Since the Antarctic atmosphere is absolutely clear, aerosol particles play an important role in the atmosphere because of their effects on the radiation budget and consequently on climate and climate change, which is in particular true for aerosols from marine environments (O‘Dowd et al., 2007). Currently, the focus is on their formation and understanding which gaseous compounds participate in it (O‘Dowd et al., 2007) and the atmospheric processes over the most complex situation caused by the water, ice and air (Andreas et al., 2004; Bishnoi et al., 2005; Dutta et al., 2004 ). In the present Chapter, we shall concentrate only on the atmospheric phenomena, which have been captured by a shipborne acoustic sounder deployed onboard the ship Megdalena Oldendroff, which sailed along the periphery of the east Antarctic ocean in the year 2002.

3. SODAR MEASUREMENTS The group at the National Physical Laboratory, New Delhi had established an acoustic sounder (sodar) at the Indian Antarctic station, Maitri (70.76o S; 11.73o E; elevation 117m) in the year 1990-91 (Dutta et al., 1991; Dutta and Naithani, 1994; Naithani and Dutta, 1995; Gajananda et al., 2004, 2007; Kumar et al., 2007; Gera et al., 2010). This development had made India as the sixth country in the world to have a boundary layer program over Antarctica and since then, attempts have been made to install a sodar system onboard the ships sailing to Antarctica as part of various Indian Antarctic expeditions (Dutta et al., 1993, 1999, 2004, 2007; Bishnoi et al., 2005). The most successful attempt for shipborne operation was made during the 21st Indian Scientific Expedition in the year 2002, when the system was installed onboard the ship Megdalena Oldendroff, which sailed from South Africa to Antarctica. The team established it successfully and operated PC controlled system as shown in Figure 1. Figure 1 shows photograph of the antenna mounted onboard the ship and that of Dr Pawan Kurmar Sharma who installed and operated the system successfully. The system was placed on the ship around January 19, 2002 and after making several checks, it finally started functioning from January 22, 2002. At the same time, the ship was sailing; its pathway is shown in Figure 2. The ship actually sailed to the German Antarctic station, Neumayer, which is situated on the shelf itself. It is important to note that the ship cannot be anchored along the shelf during the cyclonic conditions for various reasons and therefore it is kept in motion. The square shown in Figure 2. indicates that the ship remained in this area from February 3 to March 11, 2002.


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Figure 1. Shipborne acoustic sounder antenna onboard the ship Megdalena Oldendroff and Dr Pawan Kumar Sharma operating the system electronics.

Figure 2. It indicates latitude and longitude that ship followed during its journey in Antarctica. The box indicates that the ship remained in this area from February 3 to March 11, 2002.

4. BASIC PLANETARY BOUNDARY LAYER STRUCTURES In the entire period from 22 January –March 3, 2002, which is of 984 hours, the system recorded data only for 476 hours, which is 48.37% and the rest of the data contains windy conditions, system maintenance etc.

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Out of this useful data of 476 hours, 69.9% of the time, it was surface based inversion, followed by thermal convection for 15.3% of the time and elevate inversion for 14.7% of the time (Figure 3). This indicates that even during sunny hours, it is the stability in the lower atmosphere, which dominates the lower marine planetary boundary layer close to the periphery of the east Antarctic continent.

Thermal convection 15.3% Elevated inversion 14.7% Surface based inversion 69.9%

Figure 3. Out of the total 476 hours of noise free recording by the shipborne acoustic sounder, surface based inversions dominated the occurrence followed by elevated layers and the thermal convection.

4.1 Surface Based Inversion (Stable Atmospheric Structure) Surface based inversions are the most common feature of the Antarctic environment along the shelf. On acoustic sounder records, it is seen as a thick patch with one end sticking to the ground and another showing a flat upper surface under the most stable conditions; otherwise, wind may lead to some turbulence or undulations at the upper boundary. An example of the surface based inversion is given in Figure 4. The surface based inversion is caused by the radiative cooling of the surface. The surface based inversion depicts two important parameters: (i) Thickness of the ground based inversion, and (ii) The thermal gradient The thickness can be directly read from the facsimile chart with a precision of about 10m, while the thermal gradient can be judged from the colors depicted in the chart. The Figure 4. shows that the surface based layer has about 275 m as the thickness, which is varying at different timings. This variability is caused by the radiative processes influenced by the prevailing wind. Also, many thermal gradients are imbedded in the inversion, as the depiction is not just one dark patch, rather, there are many colors are an integral part of it. This shows that there must be some wind blowing at the site, which intensified at 0645 hrs. Moreover, the lighter wind was blowing throughout the record as can be seen by the green colored vertical


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lines, indicating wind noise. The surface based inversion thickness is an important parameter and is plotted in Figure 5. This shows that surface based inversions have a high variability in terms of thickness, which can as low as just 50 m or as high as 325m. Of course, the most probable thickness lies around 150 m. However, it is important to note that the data given in this figure cannot be taken for any strong or definite conclusion, these are just preliminary observations actually meant to show that the shipborne acoustic sounder can function normally even under the most adverse Antarctic conditions, recording variability in the thermal structures of the lowest PBL.

Figure 4. An example of a surface based inversion recorded by a shipborne Acoustic sounder observed over the southern ocean along the eastern coast of Antarctica. This echogram directly gives the thickness of inversion and is an important parameter in many atmospheric applications.

Figure 5. Statistical distribution of thickness of surface based inversion in various categories. The SBI thickness has a high variability but is most probable around 150 m.

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4.2. Thermal Convection Thermal convection is an important phenomenon that is rare in the Antarctic environment but it has its own importance in transporting fine particles and biological material from the oceanic surfaces to upper atmospheric regions. In this region, since the velocity is high, it helps transportation to much longer distances (Gajananda et al., 2004). On an acoustic sounder system, thermal convection is seen as inverted cones, caused by the thermal heating of the lowest surfaces, leading to mach warmer air close to the surface of earth/ ocean than the air aloft. With the result, the warmer air rises upwards, leading to the formation of what are called thermal plumes on the acoustic sounder echograms. The thermal plumes represent region of direct vertical mixing for the fine particulate matter or biological microorganisms (Gajananda et al., 2004) and are essential to be recorded on a long-term basis in order to detect signals like global warming. In the Antarctic ocean, these may not be just caused by the thermal heating of the oceanic upper surfaces by the Sun, but the warm oceanic water compared to the adjoining air, can also lead to such a situation. The reasons of formation may be many but the most important parameter to be measured is the height up to which these thermal go. Figure 6. shows a case of thermal convection as recorded and depicted by an echogram. Many papers have been published on the interpretations of these records. In this photograph (Figure 6), the clarity of thermal plumes is seen to diminish as soon as the background winds become stronger beyond 2130 hrs. Actually, winds distort the vertical movement and also lead to generation of noises on the acoustic sounder record, these two effects combined together, make them indiscernable. The plumes are seen to be going well up to a height of 350m between 1800-1900 hrs and have a high day to day variability. This has been measured on hourly basis and is plotted in Figure 7. Similarly, in the case of thermal convection, the plume rise has variability between 100450m but most of the plumes reach up to a height of 300 m (Figure 7). It is important to note that over ocean, the development of thermal plumes may not just due to the surface heating of the upper oceanic surfaces but it can also be due to the warm water, after all, thermals indicate only relativeness in the surface and upper air temperatures.

Figure 6. Thermal plumes are an important atmospheric phenomenon in the Antarctic atmosphere as they represent surface air to be much warmer than the air aloft. The warmer surface air rushes up to form an inverted cone on the acoustic sounder echograms. The height up to which these thermal go represents the thermal mixing in the atmosphere.


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Figure 7. The occurrence of thermal convection in various height ranges as recorded by the shipborne acoustic sounder over the east Antarctic coast. As expected, it has a high variability but the most probable height attained by the plumes is around 300 m. This is an important finding and shall be useful in many models.

Figure 8. Elevated inversions in the Antarctic environment are an expected phenomenon in the PBL Shipborne acoustic sounder has revealed a variety of these layers, which have shown a high degree of variability in the height but thickness is generally between 50-80 m.

4.3. Elevated Layers / Inversions Another important feature for any site in the world is the presence of an elevated layer, which is basically a stable layer but suspended in the air (Naithani, 1995; Kumar, 2002). It may be caused by a number of atmospheric phenomenon and the most common among them are the presence of a high pressure zone, which suppresses the air towards the earth. The other cause can be the wind shear, which means two air masses of different origin may lead to the appearance of this situation (Naithani, 1995).

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An example of this layer is shown in Figure 8, wherein an elevated layer is seen to be persisting continuously for several hours. Again, the interest will be in the height and the thickness of such layers (Naithani, 1995; Kumar, 2002). In Antarctica, flow of katabatic winds close to the undulating surface of earth may lead to the formation of elevated layers (Naithani, 1995; Kumar, 2002). With the available scanty data, it is not advisable to draw a figure depicting various height ranges for the elevated layers, but, most of the layers have been between 250-350 m altitudes. It is important to note that over the Indian Antarctic station, Maitri, numerous studies have been made during 1990-96 period and a variety of elevated inversions associated with a number of phenomena have been identified (Naithani, 1995; Deb, 2009). Here, since the observational period was too short, we have not been able to really record a variety of these layers.

5. NORMAL ATMOSPHERIC PHENOMENA The acoustic sounder structures observed during the experimental period recorded a variety of structures, indicating the fact that during summer, the atmospheric conditions are variable over space and time. Figure 9. shows variable structures observed on January 24, 2002, it shows a highly variable surface based inversion, with clear jumps in the structure dynamics at 0430-0530 hrs. At the same time, the presence of elevated layer indicates that there may be two different sources of airflow. Unfortunately, we were not carrying out any supporting measurements of temperature either in the oceanic water or in the air, with the result, its interpretation is difficult. But, the observed structures are a testimony to the variability. However, this variability is created by the fact that over ocean, the water surface is highly variable in terms of type of sea ice, its age and its strength embedded over open ocean spaces. Undoubtedly, the open ocean spaces are at a much higher temperature than the areas covered by a variety of sea ice. This type of variability may not be seen on daily basis, Figure 10. shows the facsimile recorded on February 10, 2002, in which surface based inversion is predominantly present in the lower atmosphere. However, dull thermal convection seems to be appearing during 10001400 hrs. At the same time, the surface based inversion is spiky, which means, vertical movement of wind or turbulence is present in the lower atmosphere. At the same time, there have been a number of incidences of high wind speeds, again indicating atmospheric variability


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Figure 9. Highly variable facsimile picture shows a turbulent planetary boundary layer over the Southern Ocean.

Figure 10. Dominance of surface based inversion is the key for the survival of Antarctica but patches of thermal convection are indicators of atmospheric variability over the ocean.

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6. UNUSUAL PLANETARY BOUNDARY LAYER PHENOMENA Apart from the mixed types of structures, there have been two extremely important and unusual incidences over the east Antarctic region. These are discussed below:

6.1. Prolonged Persistence of Thermal Convection Figures 11 a-b show that there was a special case of thermal convection on February 2-3, 2002, wherein convection persisted continuously for almost 2 days, although there were timings when the winds were high.

Figure 11 a. An extremely important and unusual event of continuous thermal convection over the east Antarctic ocean is a subject of great scientific value and needs in-depth investigations.

This is something unique as if we see the sunlight hours, the convection can only be expected during the peak sunlight hours and that too, if we presume that there was no mixing over the ocean. On the other hand, if the oceanic water is warmer than the air, then the thermal convection can be sustained on a prolonged basis. In any case, thermal convection indicates that the surface is at least 3-4oC warmer than the air aloft and the horizontal mixing is low. It is the time when surface of ocean transports its heat to the atmosphere.


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Figure 11.b. Dull thermal convection continuing from the previous day, is again an extremely important phenomenon and calls of well planned PBL studies over the east Antarctic Ocean, which is holding many natural secrets. The most important part is that even under high winds beyond 1030 hrs., dull convection continued till 2115 hrs.

Unfortunately, we had no support of any other simultaneous data and therefore, it is difficult to comment but on the basis of the published results and the data downloaded from the Antarctic data websites, some light can be thrown as discussed below:

6.1.1. Discussion It is important to note that there was a surprising event over the east Antarctic region in early 2002, when the break-up of the Larsen B ice shelf was observed (http://www.coolantarctica.com/Antarctica%20fact%20file/science/global_warming.htm). This event has been attributed to the effects of global warming. That it occurred is beyond dispute and that it is a result of the warming of the Antarctic Peninsula where it is situated is also beyond dispute. What remains unclear is whether or not this is a taste of things to come and an indicator of an Antarctic-wide phenomena or simply a localized result of the localized warming of the Antarctic Peninsula region alone. The Larsen B ice shelf was about 220m thick (720 feet) and during a 35 day period in early 2002 lost about 3,250 km2 of ice into the ocean. It is thought to have been in existence for at least 400 years prior to this and probably as long as 12,000 years since the end of the last ice age. Such disintegration in such a short time period is therefore an extremely significant event. What now remains of the Larsen B is about 40% of what was there in 1995. It had been breaking up at what was considered to be a rapid rate anyway before this major event. The break-up is thought to be a consequence of higher temperatures and large amounts of summer melt-water running down crevasses in the ice shelf so speeding the disintegration process.

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Overall in the Antarctic Peninsula, seven ice shelves have between them declined in area by about 13,500 km2 since 1974. This melting on such a large scale cannot be explained just on the basis of warming of the air, it has to be basically warming of the water, which had dissolved the whole mass of ice. This warming or warm water must have been below the ship on February 2-3, leading to the formation of thermal convection observed for over 24 hours. A series of Southern Hemisphere experiments have been performed to study turbulent convection on a continental shelf–slope placed in a large rotating tank filled with fresh water (Liang et al., 2008). The upward ocean heat transport is generated by oceanic advection, diffusion, and convective overturning. In the Southern Ocean, convection occurs along the continental shelves of Antarctica as well as in the open ocean owing to ice formation and associated salt rejection (Baines and Condie 1998). Bitz et al. (2006) have demonstrated the strong influence of sea ice on convection and the upward ocean heat transport through freshwater transport, which makes the surface waters more stable in a greenhouse warming scenario. In support of the thermal convection, it is important to note that the synoptic pictures show that there was certainly warming over the investigation area (Figure 12).

Figure 12. Rising layer is a common phenomenon over the land and is well understood. But, over ocean and that too in Antarctica, where the ocean is the most turbulent and winds are strong, this is something unique and needs in-depth investigation.

6.2. The Rising Layer Another important and unique event is the rising layer observed on January 23, 2002 (Figure 13). The rising layer phenomenon over ocean /ice looks to be unique, as we cannot expect that over ocean, the heat will not be dissipated by the mixing of the water due to winds and thermal gradients. Of course, over land, the surface based inversion created at nigh starts moving up under the influence of solar heating of the earth‘s surface. As this inversion layer rises, underneath are the thermal plumes.


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Figure 13. Rising layer over Antarctic ocean is a unique feature on acoustic sounding as it hard to expect that the oceanic/ icy surface will not transfer energy to its own medium, rather only the upper surface will get warmer to create convection and sustain it for at least 6 hours.

In fact, it is the thermal plumes, which lift the inversion at the same time, erode it from the lower side of the inversion. In the case of brisk heating, the plumes may penetrate into the inversion and may break it within a short span of time. On the other hand, like in winter, it may take several hours or the upward moving inversion may not break at all, it may remain as a suspended layer throughout the day and then return back to ground in the evening as the heating subsides (Dutta et al., 1994; Choudhury and Mitra, 2004; Kumar et al., 2010). Over the Indian Antarctic station Maitri, an acoustic sounder was deployed in the year 1990 and here also, over a period of six years, some incidences of rising layer were noticed but such cases were not very prominent (Naithani, 1995). On the other hand, on the ship, a case of rising layer was observed and it very unique as over ocean, it cannot be expected that either ocean or ice will behave like Earth. In the ocean, some amount of mixing will always be expected and over the ice, the melted water under solar heating shall always dissolve more ice. But under exceptional circumstances, it is just possible that the energy exchange underneath the water or ice gets limited and the energy exchange takes place between the wet /icy surface and the air. But, it would certainly require a high pressure area over the observational site to ensure calm weather (calm ocean) and low winds.

6.2.1. Discussion We have scanned the whole literature to get a support for our observation but there is nothing that can be quoted with firmness. However, it is important to note that for a rising layer, the heating has to be continuous on the ground to support the development of thermal plumes underneath the rising layer. This will only be available if the mslp is high so that the atmosphere is clear to form the steep inversion and in the morning to receive the heat to warm up or erode the inversion. The atmosphere, of course, has to be still.

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Figure 14. Isobaric contours of surface msl recorded on January 22, 2002 indicate high Pressure zone (marked as H) around the ship position.

Figure 15. The sea ice erosion along the eastern coast of Antarctica has been severe in the months of January-March, 2002. Sreenivasan and Majumdar (2006).

This support is available for the synoptic pictures as seen in Figure 14. It is clear from this figure that there was indeed a high pressure area or zone between two consecutive cyclones. This is what normally happens in Antarctica (Naithani, 1995; Kumar, 2002; Gajananda et al., 2004; Ved Parkash, 2008) and the weather is altogether different in two regimes (the low pressure area and the high pressure area). The other support is from the surface temperature (Figure 15), which shows the warming over the eastern zone of Antarctica and relatively open ocean so that its albedo is low.


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Actually, the whole month of January was getting warmer as is seen from the published work of Sreenivasan and Majumdar (2006), wherein authors have reported the unusual melting and the figures are presented here as Figure 15. The calculated estimates are given in Table 1. Table 1. Sea ice areal extents and depletion statistics

Date

15.1.2002 23.1.2002

Area of Sea ice depletion Million km2

Weekly depletion Million km2

5.023 4.348

1.160 0.675

Average Weekly rate of depletion km2/day 165714 84375

CONCLUSION Antarctica is the least explored and still a mysteries continent on Earth; through acoustic sounding of the atmosphere, we have explored two of its unique secrets for the first time in the history of mankind. Both of these events throw a light on the need to continue acoustic sounding program with better coordination and planning for giving a proper interpretation for the better understanding of the water-ice-air-radiation interactions over Antarctica. After all, Antarctica holds the largest fresh water stock on Earth, the key to absorb CO2, millions of unique species and much more for the betterment of mankind on Earth.

ACKNOWLEDGMENTS The authors are grateful to Dr. B.S. Gera, who supported the development of shipborne acoustic sounder in India. Authors would like to thank members of various Indian Scientific Expedition teams, who helped in the installation of acoustic sounders onboard various ships sailing over east Antarctica. Thanks are also due to the Chairman, CSIR-SCAR for selecting and providing field support to various NPL Antarctic teams.

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Chapter 3

LAND-ICE-AIR-OCEAN INTERACTIONS IN THE SCHIRMACHER OASIS, EAST ANTARCTICA Khwairakpam Gajananda1 *, H. N. Dutta2 and Victor E Lagun3 ABSTRACT Study of the land-ice-air-ocean interaction over the Schirmacher Oasis (SO) of east Antarctica was carried out during the years 1999-2000. The research revealed that a unique ecosystem prevails over this oasis, where all the physical and biological components interact in a complex pattern. SO ecosystem is heterogeneous in nature and the estimated biomass production is low at a value of 22.5 gm m-2. The lakes are oligotrophic in nature and are of fresh water lakes. Food chain of SO is very simple and short and the energy cycle is poor due to less sunlight during austral winter. The diversity of the flora and fauna is poor and is dominated by poikilohydric microorganisms. About 34 species of primitive flora were observed and only 6 primitive invertebrate fauna were recorded. Only four species of birds were observed in SO. The migratory birds from subAntarctic islands may introduce some non-indigenous forms of plants, animals and microorganisms species to SO, but only cold tolerant variety of organisms survived. Average organic carbon content of the oasis is 1.58%, which is poor in comparison to other ecosystem of the world. The microbial enzyme activity or dehydrogenase activity is 0.008 mg TPF g soil-1 day-1 suggesting a very less microbial activity for substrate decomposition. Experimental investigation suggested that the climate at Maitri is dominated by the extreme contrasts between the seasonal inputs of solar radiation. SO experiences sub-zero mean temperature throughout the year except in the peak summer months (December and January). Pressure (average 986.5 mb) forms half yearly cycle and influenced for the formation of cyclones. The humidity and precipitation are low but have significant relationship for the growth of microorganisms. Convective atmospheric phenomena during austral summer have the potential for dispersal of the microorganisms *

E-mail: [email protected], Mobile: +251-910448842 Department of Environmental Science, Faculty of Science, Addis Ababa University, P.O. Box 1176,Addis Ababa, Ethiopia 2 Roorkee Engineering and Management Technology Institute, Shamli-247774, U.P. India 3 Arctic and Antarctic Research Institute, St. Petersburg-199397, Russia 1

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Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun in this oasis. The study suggested that the ecosystem of SO must have grown with some control of atmospheric parameters and high UV-B doses in Antarctica. Climatic parameters are limiting the survival of normally living organisms, except for cold hardiness ones. The diminutive forms of plants and animal of SO are the result of less availability of nutrient, food and harsh conditions for growth and survival. Therefore, only the cold tolerant varieties of microorganisms have evolved with time in this oasis.

1. INTRODUCTION Antarctica presents the most efficient and the most interactive land-ice-air-ocean system in the world (Dutta et al., 2007). The land-ice-air-ocean interactive system supports extreme climatic conditions in the interior of the continent. With the result, only micro flora and fauna have been able to evolve with time and survive, forming one of the most important subjects in Antarctica for human understanding (Gajananda 2003). In Antarctica, only Oasis regions get deglaciated during local summer and therefore, present the most favourable conditions for the survival, growth and function of the micro flora and fauna in the otherwise harsh climatic conditions. The deglaciation of the east Antarctic oasis might have started very rapidly, close to the Pleistocene/Holocene boundary, probably favoured by marine transgression, sea level falls and climatic warming (Melles et al., 1997). Antarctic continental soils are arid, saline and lacking in organic matter, whereas maritime soils, in wetter environment, range from structure-less lithosols to frozen peat (Hall and Walton, 1992). Two important factors in the development and diversity of terrestrial communities are water availability and the period of exposure since deglaciation. The retreat of ice sheets offers new sites for colonization by microbes, plants and animals. The interactions between snow line, freeze-thaw cycles, wet-dry cycles and the length of the summer are considered as critical in determining the extent and rate of localized changes in weathering and pedogenesis (Gajananda 2007). The implications of higher temperatures and differing precipitation regimes are considered in relation to weathering, soil development and the establishment and development of terrestrial communities of flora and fauna. A study on this subject will provide a good model of how present soils and communities developed at the end of the last glacial age. The east Antarctic region, has relatively young terrestrial and inland water ecosystems, dominated by a few or single species. These ecosystems offer a great deal of information about species adaptation and reproduction. Moreover, the coastal region is ideal for the study of dispersal and colonization across great expanses of ice and ocean (Gajananda 2003). The 8 major coastal oases of Antarctica provide the migration and immigration of organisms during austral summer. The migratory birds and Penguins migrate from various sub-Antarctic islands to these regions in summer, bringing with them various forms of seeds, propagules of plants, spores and minute invertebrates. The atmospheric boundary layer dynamics over Antarctica has been studied at many stations by acoustic sounding technique, which provides an in-depth knowledge of the PBL dynamics (Argentini et al., 1996; Gera et al., 1997; Naithani and Dutta, 1995). Acoustic sounder finds applications in the areas of fog monitoring (Beran and Hall 1974; Gajananda et al., 2007). The coastal Antarctic planetary boundary layer (PBL) experiences varying external influences both from the interior of the continent and due to the moving depressions/cyclones along the coast (Wendler and Kodama, 1994; Carrasco and Bromwich, 1997). The influence

Land-Ice-Air-Ocean Interactions in the Schirmacher Oasis, East Antarctica

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from the interior of the continent is dominated by katabatic flow of winds of varying intensities, often depositing snow/ice in the form of blowing snow, drift and blizzards (Du and Bromwich, 1992; Argentini et al., 1996; Braaten, 1997). However, cyclones push relatively warm and moist air towards the interior of the continent, leading to foggy weather condition (Naithani and Dutta 1995) and coreless nature of temperature variation over Antarctica (Wendler and Kodama, 1994; Naithani and Dutta, 1995). In the driest and coldest habitats, especially where fog and dew are major water sources, desiccation-tolerant algae or cyanobacteria, bryophytes, lichens may form the only vegetation (Alpert and Oliver 2002). At the same time, thermal convection over the ocean transports fine living materials and propagules (Gajananda et al., 2004b). During summer, the atmospheric processes and the local solar heating make the Antarctic boundary layer to be one of the most dynamical regions (Kottmeier et al., 1993; Williams and Hacker, 1992 and 1993). It can be mentioned here that the increasing scientific activities and tourisms over Antarctica has introduced new and alien species and also unwanted materials are increasing day by day. The extent of its impact on this pristine environment is yet to be ascertained precisely. Strictly speaking, vegetation should be considered to be part of the climate system on all timescales. Thus, this study presents a detailed investigation on almost all aspects of climatic/atmospheric phenomena in the Schirmacher region that influence both the terrestrial and aquatic ecology or are directly responsible for ecological control and development of this region. Results obtained from the analysis of the samples collected over the Schirmacher Oasis (SO hereafter) during the period December 1999 to January 2000 have been discussed. At the same time, support of the personal observations related to the number of ecological study and the simultaneous measurements of the atmospheric parameters, during the above period have been utilized. Since various ecological factors affect the functioning of life forms in a holistic manner (i.e. all the factors operate in conjunction and not in isolation), it becomes difficult to understand the mechanism of the nature of influence by an individual factor. To understand this mechanism of environmental influences, it is essential to study the effect of each individual factor separately, thus, by taking into account the concept of an analytical approach; the following paper has been organized accordingly.

2. MATERIAL AND METHODS The SO is mainly comprised of the Precambrian age strata consisting of acidous gneiss and crystalline slates with intrusions of gabbro-norites, gabbro-diorites and pegmatite veins. Gouging traces of the ice sheet glaciation are observed everywhere as these are preserved in the form of individual spurs, ―sheep-back rocks‖ and glacial striation at the surface of cliffs, etc. indicating that in the past, the glacier covered the Oasis. Weak development of the weathering forms on the rock surfaces and fresh traces of glacial impact indicate recent ice disappearance. The weathering of rocks releases minerals, an essential component for the survival and development of the eco-system. It may be noted that the weathering of rocks leads to the formation of sandy soil, which cannot support normal forms of plant and animal lives. At the same time, brown or black rocks absorb solar energy, leading to a much higher temperature of the rock surfaces, thus providing a better habitat for the unique micro flora and fauna of Antarctica. The channels of temporary water flows appearing in the summer months

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Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun

interconnect many lakes. The depth of channel entrenchment is different comprising 8-10 m in the break segments. In mid-summer during the period of intense melting of snowfields and the glacial slope adjoining the SO, the area of some lakes significantly increases. Numerous small lakes appear with an area of up to several tens of square meters. By genesis, the lakes of glacial origin dominate. There are many relict lakes-lagoons located at the boundary between the Oasis and the ice shelf. Both shallow (3-5 m) and deep lakes (20 to 120 m) are encountered. Water in the lakes has very low mineral and small hardness. Figure 1. gives the sampling locations, fresh water lakes, rocky areas, ice shelves, polar icecaps with the two adjacent east Antarctic researches stations namely Maitri and Novolazarevskaya. SO can be classified as a true cold desert of Antarctica (Wharton 1993). In this oasis average annual precipitation (expressed in terms of water) is between 50-150mm (Schwerdtfeger 1979). Heavy snowfall occurs when cyclonic storms over the surrounding seas push in relatively warm and moist air over the continent. This moist air freezes and is deposited as snow over the areas. The region has almost continuous daylight during the local summer and darkness during the winter. The continental character dominates climate of the SO, except in local summer when it is predominated by the intensity of solar radiation heating the exposed rocks. The weather forms depend on the position of the circumpolar trough, solar parameters, flow of katabatic winds and the position of various cyclones along the periphery of Antarctica. The circumpolar trough has a biannual movement, leading to the surface pressure level to be the highest during summer and winter periods. In contrast to the seasons normally observed over the Northern hemisphere, the seasons of Antarctica have been divided as given in table 1. The relative air humidity, on an average does not exceed 52% in a year. Under such conditions, strong evaporation and melting of snow occurs, which is probably, one of the decisive factors ensuring the existence of the oasis under the current climatic conditions. Table 2. shows the average climatic characteristics of the SO, calculated from the meteorological data recorded during 1990-96 at Maitri, Antarctica.

Figure 1. Location of the study sites in east Antarctica.


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Table 1. Different seasons of Schirmacher Oasis S No. 1.

Seasons Summer

2.

Autumn

3.

Winter

4.

Spring

Months of the season December, January and February December-January are totally sunny over the Schirmacher region Circumpolar trough is towards the periphery of Antarctica March, April and May Surface temperature is on the declining phase Circumpolar trough moves away from the continent and by Winter, it again returns close to the periphery of Antarctica. June, July and August June and July are totally dark over the SO Circumpolar trough is near to the Antarctic continent September, October and November Surface temperature is on the inclining phase Circumpolar trough starts moving towards the Southern Ocean and again in summer, it returns back to the periphery of Antarctica.

Table 2. Average climatic parameters recorded over the Schirmacher Oasis during 1990-96 Direct annual radiation Total annual radiation Absorbed annual radiation Annual radiation balance Average annual temperature Mean annual atmospheric pressure at sea level Mean annual wind speed Prevailing wind direction Mean annual relative air humidity Annual precipitation quantity Number of days with snow storms for a year Mean annual absolute air humidity Mean annual total cloudiness

43.9 kcal/cm2 93.8 kcal/cm2 69.6 kcal/cm2 23.9 kcal/cm2 -11°C 988.0 mb 10.2 m/s ESE 52% 309 mm 88 days 0.07 hPa 5.8 points

The group at the National Physical Laboratory (NPL), New Delhi has been primarily working on the Atmospheric Boundary Layer (ABL) over the SO since 1989-90. During the years 1990-1997, a monostatic acoustic sounder or Sodar was operated at the Maitri, Station (Naithani and Dutta 1995). The Sodar measurements indicate stable atmospheric condition throughout the year (~95%), except in summer, when thermal convection predominates during the noon hours (~5%). The stable atmosphere is basically due to the extreme transparency of the atmosphere, leading to the cooling of the icy surfaces. However, heating of the dry, rocky region, especially in the warmer hours of the day, causes the thermal convection. In the Antarctic environment, penetration of UV light is much deeper. However, it is influenced by the influx of suspended particulate material, sea salt etc. by the cyclones churning and pushing the warm, moist oceanic air towards the continent.

44


2.1. Atmospheric Measurements The techniques used for studying the atmospheric parameters are broadly classified into the following two categories: 1. Direct or in-situ measurement techniques, and 2. Remote sensing techniques. The direct sensing techniques include surface instruments, instrumented towers, free rising balloons, radiosonde etc and the remote sensing techniques include Sodar, satellites data, UV-B, radiosonde etc. Depending upon the meteorological parameters to be measured, both of these techniques have their own importance and are at times complementary or supplementary to one another. The precise and accurate measurements of meteorological parameters need appropriate combination of the direct and the remote sensing techniques for a better understanding of the atmospheric dynamics. The Indian Antarctic program is relatively new as the permanent Antarctic station Maitri was established only in the year 1988-89. At present both the direct and remote sensing instruments are in use at the Maitri station.

2.2. Ecological Samples Collection and Analysis In the SO the exposed landmass filled with glacial water in the streams and lakes offers a relatively warmer habitat for the development of its own ecosystem. A continuous cycle of freezing and melting in winter and summer brings a large amount of change in physicochemical and biological properties of the waters, bottom sediments and over the rocky structures. In the SO, 14 sites that were showing the growth of some biological organisms were selected for studying some important ecological parameters. Collection of water, soil, flora and fauna and records of migratory birds such as Skua, Petrels and Penguins etc. were performed at these 14 locations of the SO (figure 1). Table 3. gives the descriptions of these sites. This work has been one of the most important tasks that have been undertaken at the Maitri and over the surrounding region. The water, soil and biological samples from all the 14 different locations covering almost entirely the oasis region were studies of their physicochemical analysis. It can be mentioned here that sampling is seriously limited by the harsh weather conditions in Antarctica. It is pertinent to mention here that SO is a rocky terrain with high and low undulations, sparse nunataks and depressions, slippery ice sheets, falling glacier walls, severe blizzards etc. Sampling was also often interrupted by adverse weather conditions.

2.3. Sampling Techniques The collection of samples was done during the last week of December 1999 to 31 January 2000, which was the only favourable period for growth of flora and fauna. Samples of water and soil, flora including lichens, algae and mosses, and birds litter were collected from the study sites such as moist and dried lakes, running streams and rocky sandy soil areas, all


45

along the length of SO. The temperature was recorded at the site of collection using simple thermometer during the sampling session and compared with the daily station temperature records at Maitri. From all the 14 sites, samples of soil, water (wherever available), rocks and biological samples were collected in triplicate. The sampling and analysis were carried out based on the standard methods. Table 3. Description of the 14 sampling sites at the Schirmacher Oasis Site No. 1

Habitat type Swampy lake bank

2

Lake bank

Site No. 3

Habitat type Hilly rocky area

4

Swampy lake bank

5

Hilly and rocky area

6

Glacier melt water, lake bank Rocky area near Skua nest Near Maitri station, Zub lake bank Small dried lake, swampy area Glacier melt water, stream, small lake Dried lake, swampy and sandy area Near Novolazarevskaya lake Hilly rocky area

Algae and tardigrades dominate Mosses and mites dominate

Transition of continental ice and SO rocks

Lichen dominate

7 8 9 10 11 12 13 14

Flora and Fauna Algae, protozoans and mites dominate Algae, protozoans and mites dominate Flora and Fauna Lichen and mites dominate Algae, protozoans and mites dominates Lichen and mites dominate

Algae and mites dominate Mosses and protozoans dominate Algae and tardigrades dominate Mosses and mites dominate Algae and protozoans dominate Lichen and mites dominate

Remark Little human activities Little human activities Remark Little human activities Little human activities Little human activities Little human activities Moderate human activities High activities of human Little human activities Little human activities Little human activities High activities of human Little human activities Little human activities

3. RESULTS AND DISCUSSION Figure 2. shows the schematic flow diagram of the interactive mechanism, in which, energy (heat and momentum) flows from one form to another to support the survival of some life forms and development of Antarctic environment with time (adapted from Dutta et al., 2007).

46


Figure 2. Most efficiently coupled Land-Ice-Air-Ocean Interaction System in the World. It maintains itself strongly but gets influenced by the global changes. (Dutta et al., 2007).

In the process, cyclones churn the ocean to mix the oxygen in the oceanic water, promoting high rate of biological production. Also, due to the cyclones, long exposure of the high UV-B doses to the biological organisms is avoided due to creation of turbulent mixing in the ocean, as well as, due to the development of thick clouds and precipitation. High doses of UV-B radiations in Antarctica might also be playing a role in degrading the dead organic matter, thereby releasing various nutrients, which could be readily used by planktons, thereby rendering Antarctic Ocean as the most productive ocean in the world. At the same time, the


47

cold oceanic water has much higher capacity to retain dissolved oxygen, the most essential component in the production, growth and function of organisms, as well as to support krills and various types of fishes in the southern ocean (Dutta et al., 2007). Under natural conditions, it is found that living organisms are affected by the sum total of all ecological factors and not by any individual factor. All these factors interact and are interrelated to each other, forming a complex process. Variations in one may affect the other in measurable quantities.

3.1. Structure and Function of the SO Ecosystem The SO ecosystem is a unique and fragile ecosystem with very low species diversity both from plant and animal kingdom, non-existence of higher life forms, domination of the biotic component by lower forms of plants and invertebrate organisms surviving since millions of years. The nutrient and energy exchanges in this oasis are poor due to low productivity and low diversity of flora and fauna, and extreme environmental factors. At this juncture, it is important to mention that the main factors limiting life in the SO ecosystem are the sub-zero temperatures, severe katabatic winds, drift, blizzards, extremely low humidity, snowfall, low availability of liquid water and poor sun light even during summer months, high doses of UV radiation etc. Despite the extreme environment, some forms of life have been found in the soils, streams, lakes, rocks, glacial lake ices, and melted water pools. Microorganisms such as the prokaryote dominate while a few varieties of eukaryotes prefer less stressful sites. The flora of the oasis is dominated with several species of algae, lichen and mosses. The total faunal biodiversity of the oasis consist of nearly 10 mostly microscopic species, permanently inhabiting the region. These species include protozoans, rotifers, nematodes, tardigrades, insects, and mites; there are no land-based vertebrates. The poorly developed soils and low nutrient water bodies contain bacteria, algae, yeast, and fungi. These microorganisms interact among themselves and with their nonliving environment for both food and nutrition. Over the thousands of years, SO has resulted in the development and sustenance of one of the simplest ecosystems in the world, leading to very high species endemism in this region. The lake ecosystem in the oasis varies from brackish to freshwater in nature, depending upon the distance from the coast. In SO, the hill slopes remain covered with ice in winter, but in summer, melted water gets accumulated in the depression areas between the hills, forming lakes of various sizes. However, the quantity of water in the lakes depends on the quantity of melting water, which varies from year-to-year. The majority of the lakes are archaic, possessing no outflow, and the annual ablation rate is generally balanced by the summer ephemeral inflow of glacial meltstreams. Some lakes are very shallow, small in size and are subjected to periodic drying. In winter, all these lakes freeze. The lakes, ponds and swampy areas surveyed during the study were of fresh water in nature, varying in physical area from 1.5 sq m to 2.1 sq km; depth ranges from 1.2 to 8 m. At the same time, it has also been found that the surrounding of the lakes peripheries provides a better habitat for the organisms. Figure 3. shows possible interaction between five principal components of the environment (energy, soil nutrients, organisms, water and air) prevailing over the oasis. From this figure, we infer that the ecological factors alone cannot sustain in this interactive system, rather they are a part of the whole system (Gajananda 2003).

48


Figure 3. Simplified patterns of energy and nutrient exchange in the Schirmacher Oasis.

Consequently, looking at the roles of inorganic components which involve in material cycling, the organic compounds linking the biotic and abiotic component, climate, the prevailing organisms of the ecosystem (structure) and their holistic interaction or links in a complex pattern for energy, nutrients, food chain, evolution and control (function) etc in the SO ecosystem, give a meaningful study in terms of the traditional way of ecosystem analysis by both the structural and functional concept (Figure 3).

3.2. Biotic (Living Matter) The biological environment of Antarctica is composed of two distinct and very different ecosystems: a terrestrial ecosystem (mainly over the Oasis regions), and a marine ecosystem. Marine organisms are widely distributed around Antarctica, often in patches with high population densities. Some marine mammals, such as seals and sea birds, spend some time both on land and at sea. Sea birds also supply land-based plants with vital nutrients, but terrestrial organisms provide no nutrients for marine flora or food for marine fauna. The micro faunal density at SO was found to be high in moss associated sediments. This could be related to the availability of rich organic matter in the moss beds (Davis, 1980). The SO soil has very low organic content. SO represents a typical terrestrial ecosystem, with low organism densities and abundance. It is important to note that due to higher population densities, greater complexity, and greater continuity, the marine ecosystem of Antarctica is probably somewhat more resilient to


49

impacts than is the land-based ecosystem. The biotic component of the oasis is expressed in terms of their energy exchanges and trophic position such as producers, consumers and decomposers.

3.2.1. Producers The producers of the SO are comprised of all non vascular plants. Based on the study and collection of all the vegetated sites in the 14 study areas of SO, a total of 34 species were recorded consisting of mostly lichens, algae and mosses. The Oasis is represented by individual rare patches of lichens on rocky substrates and by moss mats on silt. A total of about 19 species of lichen have been reported in the Oasis (Pandey and Upreti 2000). In the present study 17 species of lichens were recorded. Diatoms were found to be present in waters of lakes of the oases. The algal-flora of lakes in the oasis consists of about 11 species and most of them belong to the phytoplanktonic groups dominated by cyanobacteria. On the land, the producers such as lichen, mosses and algae were found mostly on damp soils, surface of rocks, and beneath the rock surface. Wherever moisture availability is high the populations of producers are also high. As the primary productivity is very less, they may support a small fraction of living consumers. Description of the species found in the SO performing the roles of primary producers are: (i) Algae. The algal species at the SO occupied distinct levels of habitats; (a) in association with mosses (b) on damp soils (c) on quartz rocks in the water pools and (d) lake bottoms. The submerged rocks, which are directly exposed to sunlight, favored the growth of thin reddish brown to blue-green encrustation. These crusts were composed of both N2 and non-N2-fixing species. The cyanobacterial patches only covered with high amount of mucilage were abundant on the soil surface near the edge of the stream and were also observed in the depressions created on turning the small rocks and stones in slow running streams. Glacier does not support growth of algae and cyanobacteria. The pond and upper stream support less growth of algae and cyanobacteria. However, their growth was abundant and readily visible on the surface of the rocks, boulders and weathered soil of the middle portion of the stream of site no. 2. Algae are also found under rocks, particularly light-coloured quartz stones, where the microclimate is more favourable than in the surrounding sand or soil. This strategy enables them to scrape a humble living in this harsh environment. The species richness of algae was highest in the streams. Analysis of SO lake water showed the presence of Oscillatoria, Chroococcus, Synechocystis and some diatom species. Phormidium frigidum constitutes an important and dominant species of algal flora, which is non-N2-fixing species. Table 4. shows the different types of algae found at the SO. Majority of the algae recorded at the SO possess tough and collared mucilage. These properties of algae may help in two possible ways (a) light filtration and (b) increasing water retention capacity. Komarek and Ruzicka (1966) found that the ice-covered lakes of SO were highly productive due to algae. The main component of flora is the Phormidium species, which forms large fan shaped colonies supersaturating the water with oxygen. (ii) Lichens. Lichens are the most widespread flora of the SO. Lichens such as Rhizocarpon flavum, Acarospora gwynnii, Xanthoria elegans, Buellia pallida,

50

Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun Lecidia cancariformis, Lecanora fuscobrumnea, Umbilicaria aprina dominate in the oasis. It is interesting to note that lichens are found growing even on rock surfaces, where availability of nutrients is low. This is due to the fact that many of these rocks are porous; so as to retain little amount of water. The lichens released some weak acids themselves, resulting in the dissolution of some nutrients from the rocks (Pandey and Upreti, 2000; Stoutjesdijk and Barkman, 1991; Upreti and Pant, 1995). At the same time, rock surfaces become much warmer under sunlight than the soil itself, leading to a favorable conditions for lichens to grow. Under the microscope, it has been observed that the lichens penetrate the upper transparent coat of the rock. In all the samples collected, lichens are present mainly in the water free rocky samples. Their population density is high in the oasis. Lichen population and density are more favourable in humid environment. They are found in abundance in all the forms of soil substrates. Lichens are known to be the initial colonizers of bare rocks starting the succession process. The growth of lichens on the rocks of SO indicates that they might be having the way for some more forms of life by creating gradually a little more congenial conditions for growth in years to come. Table 5. gives the various descriptions and the dispersal potential of the lichen communities over SO. (iii) Mosses. The moss species available over the SO are given in Table 6. the most dominant one is Bryum argenteum, which is capable of photosynthesis in low light and low temperature. Photosynthesis of this moss can start within a few hours of thawing after a prolonged period of freezing and almost immediately following short snowfall periods. Moss (Bryum species) has been found to be associated with algae such as Nostoc species and Stigonema species. Moss turfs are seen mainly on the icemelt water streams from the glaciers. They tend to grow more on the places with finer sand than the coarse sand with pebbles (Table 6). Maximum biomass of the Zub Lake has been estimated as ~40.63 gm m-2 and it comprises mainly of moss turfs (Gajananda 2003). The moss habitat forms the substratum for the micro invertebrates such as tardigrades, nematodes and rotifers. Only in site no. 9 (Figure 1), mosses were not observed. This may be due to the fact that the sample was collected from water free dry lake region of SO. Mosses were found in abundance in other samples. In terms of density and population moss Bryum argenteum is amongst the dominant flora of the SO.

3.2.2. Consumers The real consumers of the oasis are mainly the primary consumers composed of invertebrate micro-fauna. These micro-fauna have adapted to the extreme living conditions throughout the years. However, some of the larger birds (Skua, Snow Petrels, Storm Petrels and stray Penguins) migrate to this region only during the local summer. All the birds depend on the sea for their food except Skua, which also feeds on the dead remains of Penguins, Petrel and their chicks. Thus, Skua acts as a detritivore and scavenger. It may be noted that these birds except Penguins, migrate purposely towards the oasis region, while Penguins come by mistake, losing their sense of direction. Instead of moving towards the coast in search of food, they move towards the continent. The death of such Penguins serves the purpose of the scavenger bird Skua and the remains add to nutrient pool of the oasis. The invertebrate terrestrial fauna of SO mainly inhabited in the soil and in vegetation. They range from protozoa (single-celled creatures), rotifers, tardigrades and nematodes to arthropods


51

(mainly mites and springtails, midge). The largest invertebrate found is the wingless midge (Belgica antarctica), which grows to 12 mm long. The distribution of tardigrades, nematodes and rotifers are more near surface soil area. The occurrence of micro fauna on the top layers of the soil may be due to a slight rise in temperature due to sunshine, availability of food etc. They may also migrate up and down in the soil. Further studies might reveal the local variations due to temperature and light difference the occurrence of these fauna in the soil. Heywood (1979) has also shown that many invertebrates are plant feeders. It may be stated here, that the species reported in 8 lakes and 4 swampy areas of SO are those that are distributed widely in Antarctic lakes with similar behavioural pattern that is thriving well in sediments rich in micro flora and organic matter. Densities of these micro fauna vary from 20,000 to more than 14 million animals per m2 (Bonner and Walton, 1985). Ingole et al., (1987) observed a maximum tardigrade density of 140 per m2 and 272 per m2 of nematodes at Zub Lake. However, a maximum of 35 per m2 of Tardigrades, 21 per m2 of nematodes and 10 per 2 m of rotifers were observed in the present study, which is much lower than at the bottom of the lake in SO. The low density of micro-fauna in the present study may be due to less food availability (moss growth) on the land. Population density of these micro-fauna is reported to show variations with light, temperature, level of blizzard, relative humidity and food, these being the major determinants (Fleeger and Hummon, 1975; Morgan, 1977). All of the Antarctic animals have adapted to life in extremely cold conditions. The springtails and mites live under rocks in the SO. A brief description of the primary consumers of SO is provided as follows. Table 4. Taxonomic assessment, identification, habitats descriptions and the dispersal potential of the algal communities of Schirmacher Oasis, East Antarctica S No.

Algal class, order and species

Habitat descriptions

Shapes and sizes (μm), color

Forms of possible dispersal

Comments

1

Class: Cyanophyceae Order: Nostocales Calothrix gracilis Lyngbya aeustuarii Nostoc commune Oscillatoria limosa Phormidium frigidum Schizithrix Order: Chroococcales Aphanocapsa Aphanothece nidulans Gloeocapsa kuetzingiana

Found in all the sites; fresh water lakes, streams, swamps, ponds etc. association with lichen and mosses; forming green scum; black epilithic crusts on rock surfaces

Ellipsoidal, Spherical, irregular; motile or non motile; 1-90; both unicellular or multicellular; colonial

Independent dispersal of spores and cysts may occur; vegetative cells, spores and cysts

Generally aggregated, chlorophyll present, thallus undifferentiated thalloid plant body

52

Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun Table 4. (Contnued) S No.

Algal class, order and species



Forms of possible dispersal

Comments

Spherical, ellipsoidal, irregular 1-80

Same

Same

Order: Chlorococcales Chlorococcum 3

Class: Baccilariophycea e Order: Pennales Hantzschia Pinnularia borealis

Table 5. Taxonomic assessment, identification, habitats, descriptions and the dispersal potential of the lichen communities of Schirmacher Oasis, East Antarctica S No.

Lichen class, order and species

Sites, Habitat descriptions and date

Shapes and sizes (μm), colour Spherical, irregular; 35-70; yellowish green

Forms of possible dispersal Independent dispersal of ascospores; Soredia, Isidia

Comments

1

Acarospora A. gwynnii A. williamsi

2

Alectoria A.minuscule

Very common on shady place, moraine and rocks; generally absent in habitats close to melt water; Near Russian and Indian Stations Cracks and surface of rocks, rocks inside water

Same

Same

Moraine, amongst pebbles, rocks

Same

Same

Carbonea C. capsulata

Grow on rocks of small depressions, Near Russian station along the lake.

White mat with compressed areolate

Same

5

Lecidea L.cancariformis

Same; black apothecia

Same

6

Lecanora L.fuscobrumnea

Very common, endolithic lichen, grow in dry rocky surface, mostly on the leeward sides of rocks, along the dried stream Grow on rocks, sheltered place,

Same; Fruticose; forms varicose masses; filamentous Same; umbilicate thallus; crustose and saxicolous Same; amorphous thallus; apothecia on the tops and sides of the stipes Same

3

Buellia B.pallida

4

yellowdark brown disc,

Same

Squamulose areolate and crustose; thallus fragments very common

Same; lichen with crowded mats of apothecia

Land-Ice-Air-Ocean Interactions in the Schirmacher Oasis, East Antarctica S No.

Lichen class, order and species


7

Lepraria Lepraria membranacea

8

Physcia P.caesia

9

Polycauliona P. murrayi

Very common lichen of SO, grow on moist place, decayed mosses Common and luxuriant lichen; Pebbles and small rocks Common lichen on rocks, sandy soils, well watered areas

8

Porpidia P.species

9

Rhizocarpon R.flavum R.species

10

Rinodina R.Species

11

Umbilicaria U.aprina U.decussata

12

Xanthoria X.elegans

Stones, pebbles, Rocks; leeward sides of rocks Rocks, stones, pebbles; streams, ponds, lakes

Most common lichen on rocks; decayed mosses tufts, algae etc. Most common lichen on rocks, stream, lakes, ponds, sandy soil; elevated well sunlight area Sandy soil near Novolazarevskaya lake

53

Shapes and sizes (μm), colour Powdery, Yellow colored

Forms of possible dispersal Same

Comments

Same; whitish,

Same

Same; foliose lichen

Orangeblack circular hapteron Same; black apothecia Same; yellowblack and white-black colored Same; black granular

Same

Same; fruticose lichen; erect tufts

Same

Same

Same

Same

Same

Same; varicose lichen

Thallus 0.1 cm to 18 cm diameter

Same

Same; foliose lichen; cosmopolitan

Same; red lichen

Same

Same; lobate lichen

Same

Table 6. Taxonomic assessment, identification, habitats, descriptions and the dispersal potential of the mosses (bryophytes) communities of Schirmacher Oasis, East Antarctica S No.

Mosses family, Genus and species


Shapes and sizes (μm), colour

1.

Bryaceae Bryum argenteum(Hedw.) Bryum pseudotriquetreum (Hedw.)

Very Common; moist soils, sheltered place of rocks; banks of lakes, ponds and swampy areas; close to snow banks; biogenic remains; birds nest remains etc.

Globose, tetrahedral, Variable in length; 10-25; yellowish brown to brownish, red stem, deep green

Forms of possible dispersal Spores, Gemmae

Comments

Sporophyte present; seta 1.5-4.5 cm long; whitish colour; capsulated; vegetative fragments dispersal observed

54

Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun Table 6. (Continued)

S No.

Mosses family, Genus and species


Shapes and sizes (μm), colour

2.

Pottiaceae Bryoerythrophyllu m recurviroste (Hedw.) Pottia cf. heimii (Hedw)

Not common; banks of lakes, ponds and swampy areas; close to snow banks; around the nest remains etc.

3.

Ditrichaceae Cedratondon purpureus (Hedw.)

Common; Same as Sl No. 1

4.

Grimmiaceae Grimmia sps.

Common; Same as S No. 1.

Globose and tetrahedral; 10-25; reddish green to brown, yellowish green to green, reddish nerves Globose, tetrahedral, Variable in length; 10-25; brownish green, yellow, reddish Globose, tetrahedral, Variable in length; 6-20; brownish green, green turfs

Forms of possible dispersal Gemmae, vegetative fragments

Comments

Gemmae, vegetative fragments

Non Sporophyte vegetative fragments dispersal observed

Gemmae, vegetative fragments

Non Sporophyte; vegetative fragments dispersal observed

NonSporophyte; vegetative fragments dispersal observed.

3.2.2.1. Primary Consumers The primary consumers of the SO are very less in comparison to others ecosystem types. The primary consumers comprise of minute organisms, which consume very little amount of food available in this oasis. Table 7. shows the various primary consumers of the oasis. During the present investigation, six different micro faunal groups viz., Protozoa, Nematoda, Rotifera, Tardigrada, Collembola and Mites have been recorded from SO area (Table 7). Some groups of parasitic insects are also found in this region. It is found that nematodes and protozoans have higher range of adaptability in this harsh environmental condition. Table 7. shows that most of the micro-faunal groups were found from ice free areas, except mites, which were not found in ice-free water. Collembola was not found in sites mostly covered with ice water. All the micro faunal groups were found in both running and stagnant water except mites, which were available only in running water. Thus from the present data (Table 7) it may be concluded that Protozoa, Rotifera and Nematoda were distributed in generalized way and in all different conditions of the water and moss habitat type. (i) Protozoa. Maximum number of Testacids Protozoan species (7 sps) followed by 6 sps of Rhizopods have been observed in SO. Amongst ciliates, Oxytricha fallax is found in all the lakes. Testacids Corythion dubium was found to be most dominant and cosmopolitan, followed by Assulina muscorum and Arcella Sp. One genus (Parmulina Penard) of protozoan species of Schirmacher area is cosmopolitan to soil


55

and moss dwelling forms. However, earlier workers found that several species are endemic to SO. (ii) Rotifer. The Rotifers are a group of small usually microscopic, Pseudocoelomate animals. They are also called ‗Rotatoria‘ or wheel animalcules. Only one species viz., Philidina gregaria has been observed and collected from SO. (iii) Tardigrada. Tardigrades have well defined head and four trunk segments with 4 pairs of short legs bearing claws, which are used to walk along underwater surfaces. Tardigrades have the ability to ‗hibernate‘ (cryptobiosis) in which they can survive extreme thermal condition, exposure to highly toxic chemicals, drying out, etc. In this process, they are capable of withstanding very cold condition (-900 C) by passing into a state of very low metabolic activity. This phenomenon is also referred to as anabiosis. The body surface is covered with ornamented plates, sometimes bearing spines or hairs. Many species have eyes. The mouth is terminal or ventroterminal. Sexes are separate and the females are oviparous. Development is direct, the cuticle being moulted. Two species of tardigrades are found in SO, namely Hypsibius ckhilenesis and Macrobiotus polaris. The ability to tolerate severe desiccation, anhydrobiosis survival etc are the advantages for the widespread distribution of many species of tardigrades. In spite of the short summer season tardigrades multiply quickly and become very abundant. They reproduce by parthenogenesis. (iv) Nematoda. Three species of nematodes are found in SO viz. Tylenchorhychus sp., Dorylaimoides sp and Rhabditis. Hazra (1994) recorded 5 genera from SO for the first time. The genus Tylenchorhynchus and Dorylaimoides, which occur widespread in the Indian continent, might have been transported along with agricultural products to the SO especially in the Zub lake area (Venkataraman 1998). (v) Springtail (Collembola). Two species out of two families viz., Isotomidae and Entomobryidae were observed from SO. Isotomidae is larger and have slender body, they can jump actively, whereas smaller type Entomobryidae is dorso-ventrally flattened with broad oval abdomen and moves slow to hide in the soil. The body segments are more obvious in larger type. The springtails were collected from soil with micro-plants. They mainly inhabited the soils where little growth of plants is possible. The population densities of larger and smaller types of springtails were counted as 6 to 28 and 12 to 56, respectively in 100 gm of soil sample. So far 20 species of springtails have been reported from the Antarctic continent (Laws, 1977). (vi) Mites. Mites, which belong to the spider family, are the commonest land animals. It is the world‘s most southerly indigenous animal found as far south as 850 S. Two species of mite‘s viz., Tyrophagus sp and another unidentified species of family Scutacaridae from SO have been reported by earlier workers (Mitra, 1999). Many of the mites avoid freezing by a physical process known as ‗super-cooling‘, whereby their body fluids are maintained in a liquid state in temperatures below their normal freezing point (Pan and Shimada 1991). Their ability to synthesize glycerol, antifreeze, enables them to survive temperatures of –350 C (Block et al., 1994). The population varied from 7 to 76 in 100 gm soil. Acarina represents the principal Arthropod group and these mites are large and relatively well-known group in the region. (vii) Insects. Compared to other regions, insects are scarce and much smaller in size over the oasis. The type of living habitat for most of them has been found to be

56

Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun parasitic, like lice, which live in the feathers and fur of birds and seals, where they remain protected from the harsh climate for most of the time. Collembola (springtails) are the only free-living insects, which feed on algae and fungi, and remain dormant in winter. However, some of the parasitic insects do fall on the surface from feathers of the birds, but they do not survive during the freezing periods. Table 7. Primary consumers of SO S No.

Microconsumers (species)


1

Protozoa

2

Rotifer

Most dominant sps, lakes, soil, moss dwelling forms Partly freshwater but prefer moist terrestrial moss-water habitat

3

Tardigrada

4

Nematoda

5

Springtail (Collembola)

6

Insects

7

Mites

Non-planktonic; Found in aquatic mosses and algae, mud, ponds and lakes. Active tardigrades found even in droplets and film of water on terrestrial wet mosses. Not common; found in soils, plants and dead organic materials, terrestrial moist soil, moss-fresh-water etc. Found mostly in soil; damped place with small amount of micro flora Scarce; Parasitic; found mainly inside the stations; birds feathers etc. Commonest land animals


Comments

Small microscopic, ½ mm long; reddish color.

Also known as ‗rotatoria‘ or wheel animalcules Commonly known as ‗water bear‘; Cryptobiosis; reproduce by parthenogenesis

About 1 mm long

About 0.6 mm long, 0.03 mm wide and weighs about 0.55 micrograms About 0.65mm to 1.25 mm long; white in color Smaller compare to mainland parasites

About 0.3 mm long; whitish in color; oval shape with dorsally convex body

Only free living insect Mostly parasitic to birds

World‘s most southernly indigenous animal; process of "supercooling"


57

3.2.2.2. Secondary Consumers Birds: Penguins (Emperor, King, and Adélie), petrels (Snow, Wilson's storm, Blackbellied storm, and Gray-backed storm), Brown Skua, and Arctic Tern were seen during the study period. Most typical and abundant bird of the oasis is the Adélie penguins and Brown Skua. Their description and habitat are given as follows: (i) (i). Penguins. Penguins are the common flightless, aquatic birds of the southern hemisphere. The largest species are the Emperor Penguin, which may attain a height of more than 120 cm (48 in), and the King Penguin, from 91 to 97 cm (36 to 38 in) in height. Adelie penguins are the most widespread penguins in Antarctica and they are smaller than Emperor and King Penguins. All these species of penguins are found on the Antarctic ice. They evolved from earlier flying ancestors but have become highly specialized for swimming. Their wings resemble the paddles of other swimming vertebrates. The ability to withstand intense cold is one of the penguin's greatest advantages. Most penguins have small feet, wings, and heads. The relatively small body parts in comparison to the bird‘s volume results in excellent heat conservation. In addition, many penguins have a thick insulating layer of fat under the skin. The emperor penguin, which may weigh 27 to 32 kg, appears to be the best equipped of all. Penguins usually walk or hop and toboggan along on their breasts, pushing with wings and feet. Penguins feed on fish, cuttlefish, crustaceans, and other small sea animals. On land, they make colonies (rookeries), which often numbered in the hundreds of thousands. The greatest concentrations of penguins are seen in rookeries, where the birds gather to breed. The emperor penguin breeds in one of the world's most inhospitable regions during one of the coldest periods of the year, laying and incubating its eggs in temperatures as low as -620 C. Most species of penguin lay a clutch of two eggs, which are white or greenish in colour. Incubation periods vary according to species. The Adélie‘s incubate their eggs in the open nests formed of stones or sticks. King and Emperor penguins build no nests; in these species the bird holds its single egg on the top of its feet, hunching down over it so that a fold of abdominal skin covers and warms the egg. In general, both sexes incubate the eggs and feed the young. The male Adélie penguin usually fasts while incubating the eggs for the first two weeks, allowing the female to return to the sea to feed and bathe. The male has been known to fast during the entire time that the nesting territory is established and defended, courtship takes place, and the eggs are laid and incubated. Most penguin chicks are covered with a sooty-grey down at hatching, although some have a pattern of soft greys and whites. Natural enemies of the penguin include leopard seals, killer whales and in the case of young chicks and eggs, Skuas. Today, the populations of penguins have increased due to lesser human perturbation. Scientific classification: Penguins make up the order Sphenisciformes. The king penguin is classified as Aptenodytes patagonica, the emperor penguin as Aptenodytes forsteri. The six other species that have yellowish feather crests on the sides of their heads make up the genus Eudyptes. The Adelie Penguin as Pygoscelis adeliae. (ii) Skua (Catharacta macromicii). Skuas are brown coloured predatory sea birds. The lower side of the wing feathers are light colour and flashy. Their beak is like the common kites and is strongly hooked. The beak is covered at the base with a flat horny sheath. The black feet are like that of the common duck and are strongly

58

Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun clawed. They have a rapid, sustained and powerful flight, which enables them to prey on many birds. Skuas prey on chicks and eggs, particularly those of penguins and take a heavy toll of small petrels. Skuas characteristically are territorial bird; they defend intruders of their territories by raising and squalling with open wings over the back. The females are larger than males and are more aggressive and rapacious. Females are particularly aggressive in defending their young chicks from intruders. The Skuas fight, dive, squall, flap and acrobat to ward off the intruders.

3.2.3. Decomposers At the present study the decomposer assessment could not be undertaken. However, some earlier workers have reported the following microorganisms. Bacteria, yeasts and fungi: The dominant species of bacteria present in SO are the gram-positive rod identified as Pseudomonas fluoresceus, P. putida and P. syringae and gram-positive cocci as Micrococcus genus Arthrobacter (Shivaji et al., 1989a, 1989b). Matondkar and Prabhu (1986) reported bacterial counts in peripherial lake sediments in January 1985 to range from 21x105 numbers g-1 of dry sediment. In loam and moss soil, their concentration varied from 12x102 to 2.5 x 103 and 10 x 102 to 1.2 x 103 per g dry weight respectively. Moss algae and moist soil were rich in bacterial counts as compared to dry sand. Evans et al., 1997 has reported bacterial counts to vary from (1 to 25) 106 per g dry weight in some of the Antarctic lake sediments and majority of the bacteria as psychrotrophs. On the other hand phylogeny of obligately anaerobic, coiled bacterium from Ace Lake, Antarctica, was isolated by Franzmann and Rohde, (1991); Franzmann and Dobson (1993), which they believed to have been introduced by humans. Franzmann et al., (1991) also found that Carnobacterium funditum and Carnobacterium alterfunditum are psychrotrophic, lactic acid-producing bacteria found at anoxic waters in Ace Lake, Antarctica. Matondkar and Prabhu (1986) studied the effect of temperature on bacterial population of SO, and found that temperature has minimal effect on these microorganisms indicating their high degree of tolerance to low temperature. Shivaji, et al., 1989c isolated fungal populations and found Penicilium species, consisting of P. olivicolor, P. corylophulum, P. viridicatum, P. chrysogenum, P. waksmanii, and P. camemberti to dominate the fungi. Few colonies of Fusarium oxysporum and Paecilumyces variotii were also reported. Similarly, in the soil samples of SO, 8 strains of yeasts Rhodotorula rubra, one Bullera alba, one diamorphic Candida humicola and one C. famata and the remaining two tentatively identified as C. ingeniosa and C. auricularia was reported (Ray et al., 1989). In the dry valleys elsewhere in Antarctica various yeast strains such as Cryptococcus, Candida, Rhodotorula and others have been reported (Vishniac and Kurtzman, 1992; Vishniac 1993).

3.3. Food Chain and Food Web Food chains and food webs are the basic units of ecosystem, since all the energy and materials cycling take place around them. The food webs of SO can be represented as follows (Figure 4). The food chains and webs are much simpler at SO terrestrial ecosystem as compared to any other ecosystem, particularly in view of the non-existence of higher organisms of plant or animal kingdom. The only higher animals include some migratory birds.


59

Figure 4. Simplified Food Webs of the Terrestrial Ecosystem of Schirmacher Oasis.

The carbohydrates produced by the algae and mosses through photosynthesis are the main source of food for the primary consumers like mites, tardigrades, protozoans, rotifers and midges etc. More information is needed on the actual decomposition process in the Antarctic ecosystem where temperature is very low. The primary production is very little and as such the proportion of plant biomass passing into detritus component is presumably quite low as most of the primary production is grazed by the herbivores. Detailed investigations are required to understand the energy flow and nutrient cycling through the terrestrial ecosystem at SO through the simple food chain. During the Antarctic winter when it is dark, there is no photosynthesis by many of the producers. The plant eating primary consumers living on algae grew only during the summer.

3.4. Characteristics of SO Community 3.4.1. Frequency Distribution The data collected for ecological community study with the help of ‗line transect method‘ during the months of December 1999 to January 2000 are given in Table 8. For preparing the frequency diagram of the SO the values were counted and calculated as % of the total species for five different classes as laid down by Raunkiaer’s (1934). The law of frequency is given as: > A>B>C=D<E < The % values of normal frequency diagram of different frequency classes are: A=53, B=14, C=9, D=8 and E=16. From table 8, the % frequency of different classes was calculated as follows: Calculation of Frequency Class (%):

60

Khwairakpam Gajananda, H. N. Dutta and Victor E Lagun i)

Frequency Class A % = (No. of sampling sampling units) x 100 = (11/25) x 100 = 44 ii) Frequency Class B % = (No. of sampling sampling units) x 100 = (8/25) x 100 = 32 iii) Frequency Class C % = (No. of sampling sampling units) x 100 = (3/25) x 100 = 12 iv) Frequency Class D % = (No. of sampling sampling units) x 100 = (3/25) x 100 = 12

unit of species occurrence/Total no. of unit of species occurrence/Total no. of unit of species occurrence/Total no. of unit of species occurrence/Total no. of

Table 8. Frequency of plant species in Schirmacher Oasis (estimated by ‘Line Transect’ method) S No.

Vegetation Groups

Name of Species

Frequency (%)

I

Algae

II

Lichen

III

Mosses

Lyngbya aeustuarii Nostoc commune Oscillatoria limosa Phormidium fragile Aphanothece nidulans Chlorococcum Pinnularia borealis Acarospora gwynnii Buellia pallida Carbonea capsulata Lecidea cancariformis Lepraria membranacea Physcia caesia Polycauliona murrayi Rhizocarpon flavum Rinodina Species Umbilicaria aprina Umbilicaria decussata X.elegans Bryum argenteum Bryum pseuotriquetreum Bryoerythrophyllum Recurviroste Cedratondon purpureus Grimmia sps. Unknown

60 60 80 80 20 40 40 40 40 20 30 20 10 30 20 10 30 30 10 60 20 10

Frequency class To which species belongs C C D D A B B B B A B A A B A A B B A C A A

20 20 70

A A D

IV

Unknown

The above-calculated values are plotted and compared with the normal frequency classes (Figure 5.a and b). From the figure 5.b. it is clear that values of frequency classes B, C and D of figure 5.b. is comparatively higher than the respective values in normal frequency diagram (Figure 5.a). Thus, the plant community of the SO is heterogeneous in character. It can also be mentioned here that the value of frequency class E in figure 5.b is nil. Thus, none of the


61

species showed 80-100% constancy. This indicates that the SO environment does not provide suitable habitat for any species to occur homogenously. The heterogeneity is linked to microenvironments in the oasis providing congenial conditions for growth, both spatially and temporally. Also from table 8 it is found that the dominant algal species are Oscillatoria limosa and Phormidium fragile both of which are blue green algae, the moss species are dominated by Bryum argenteum and the lichen species by Acarospora gwynnii. It is important to note here that amongst all the plant groups, algal species dominate, whereas, the occurrences of moss and lichen species is lesser, which could be because the study sites are mostly aquatic in nature and it is true that out of 14 selected sampling 8 sites are just the banks of lakes, two dried lakes and four swampy areas. Some unknown species also occurred, which seemed to be some moss in close association with some lichen or algae, and could not be identified. It is very interesting to note that all the algal mats were dominantly consisting of cyanobacteria or blue green algae. Heterocystous cyanobacteria capable of independent nitrogen fixation like Nostoc Commune were mostly present on ice surface and lake bank over snowmelt. Pinnate diatom Pinnularia was found on surface layers of lift-off and often seen sliding between blue green algal mats. The only green algae found in the present transect study was Chlorococcum. This is in contrast to many other reports from snow regions where Chlorophyta members are present in abundance. Earlier Ling and Seppelt (1993) reported Chloromonas Subroleosa belonging to chlorophyta from Antarctica, which gave a red color to the snow attributed to the development of pigment in the species.

Figure 5. A and B. Shows the Raunkiaer‘s normal frequency diagram and the frequency diagram of the Schirmacher Oasis community. Frequency classes B, C and D of diagram B are relatively higher than A, thus the community is heterogeneous.

62


Rare occurrence of green algae and dominance of blue green algae in the SO of Antarctica suggests that these cyanobacterial species are better adapted to the prevailing extremities of climatic conditions in Antarctica. The prokaryotic cell wall struture consist of diaminopimellic acid and muramic acid presumably provides better resistance to the cells. It also seems likely that the green algae are not so efficient in withstanding the freezing and thawing. In an experiment conducted by Bidigare et al., (1993), samples of red and green Chlamydomonas (Chlorophyta) when exposed to freezing and thawing resulted in lysis of the green cells whereas the red cells survived, which was due to increased membrane fluidity. Cyanobacteria containing phyco-cyanin (blue pigment) and phyco-erythrin (red pigment) seem to have more resistance to the stress conditions of Antarctica.

3.4.2. Plant Biomass (Standing Crop) Biomass or the standing crop present in a population at any given time is expressed as weight per unit area and is given in Table 9. for various study sites of SO. The estimated standing crop (dry weight) or biomass per square meter of SO varies from 6.25 to 45.31 gm-2 in various study sites. Various methods have been used by different workers to estimate the net primary production of an ecosystem and mostly a time-series data of harvest method is employed. However, Antarctic ecosystem is unique as it experiences long periods about two months of complete dark followed by two months of complete light. Again, it is during the summer period (December to February) that the snowmelts and favourable periods for some plant growth set in. Thus, the data on standing crop of biomass collected in the present study on December 31, 1999 to January 18, 2000 represent the peak growth and peak biomass and have therefore been considered as an estimate of net primary production (NPP) of the SO ecosystem (Odum 1971). Table 9. Peak Plant Biomass (gm-2) in terms of fresh weight and dry weight for the vegetation at different study sites of Schirmacher Oasis (the values are mean of three replicates)

Site No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Biomass (gm-2) Fresh weight 11.5 15.35 12.5 9.54 14.5 26.7 8.5 21.75 7.5 21.75 17.45 8.5 11.6 21.8

Dry Weight 2.8 3.25 2.95 2.2 3.45 7.25 1 6.5 1.2 6.2 4.65 1.2 2.46 5.3

Moisture Content % 310.71 372.31 323.73 333.64 320.29 268.28 750 234.62 525 250.81 275.27 608.33 371.54 311.32

17.5 20.31 18.44 13.75 21.56 45.31 6.25 40.63 7.5 38.75 29.06 7.5 15.38 33.13

Mean (±1 S.E)

14.92 (± 4.30)

3.60 (± 4.32)

375.42 (± 4.31)

22.50 (± 4.32)

Biomass per unit area


63

It must, however, be mentioned here, that these values of NPP are highly biased because they correspond to the study sites where conditions are favourable for growth. Even during summer, there are large areas bearing no vegetation at all. The present estimates of NPP therefore give an estimate of the potential of production of SO under the prevailing conditions. The average NPP value of the SO (22.5 gm-2), when compared to other stressful ecosystems of the world is still found to be very little.

3.5. Abiotic Component (Standing State) The study of abiotic components of the SO consists of rocks, ice, snow, and various inorganic nutrients, soil, melted water, sunlight and the climatic parameters. The soil over the SO has been classified as dry, polar desert soil, with a variety of textures and their occurrence has been found to be limited to the deglaciated (ice-free) area. Organic compound, such as ‗humus‘ (that links the biotic and abiotic component of the ecosystem), is extremely poor in this region. In table 10. the analysis of the various water, soils and biological samples for determining the ‗standing state‘ of the ecosystem and the atmospheric condition of the particular dates are given. Table 10. shows the physicochemical analysis of water (0 to 1m depths), biological and organic carbon of soils collected during December 1999 to January 2000, from 14 different sites with the atmospheric condition of the particular dates of SO. The results of the various analyses presented in table 10 are given below.

3.5.1. Physicochemical Analysis of Waters and Soils Samples: The average value of pH in the water of 14 different sites is 7.5, indicating that the water bodies are slightly of alkaline nature. This alkaline nature may be due to the photosynthesis by the algae and diatom mat present at the bottom of the lake (Gajananda and Dutta, 2005). The average Ca and Mg content of all the lakes have been measured to be 17.6 and 4.8 mg l-1, respectively. Dissolved Oxygen is also high at the value of 7.5 mg l-1. The DO, pH, Ca and Mg contents indicate that the lakes are well aerated and offer to be sources of freshwater supply to the oasis (Gajananda et al 2004a). Over the SO, these few important parameters of physicochemical characteristics of freshwater lakes were correlated with the available fauna (Table 10). 3.5.2. pH, Dissolved Oxygen and Conductivity pH in the surface waters ranged from 6.9 to 8.20, showing alkaline nature of the lakes. In site no. 4 (table 10), the pH in the surface water was high, while in site no. 8 the reverse was observed. Such changes may reflect the chemical composition of the bedrock sediments of each of the lakes and also human perturbances. The DO of lakes ranges between 6.1 to 8.4 mg l-1. The maximum was recorded from site no. 8. The conductivity of the lakes varied between 8-15μ mhos cm-1 (Gajananda et al., 2004a). The DO levels of the lakes indicate high quality water. The high DO levels can also be due to good photosynthetic activity of the algae present in the water (Gajananda et al., 2004a).

Table 10. Physicochemical analyses of the various water, soils and biological samples and the atmospheric conditions of the particular dates S. No 1 2 3 4

Ecological Parameters Surface Air Temp. (0C) MSL Pressure (mb) Wind Speed (m/s) UV-B (MED/Hr)

Dates and sites of the samples collected Dec. 30, 1999 Jan. 7, 2000 I II III IV V

Jan. 13, 2000 VII VIII

IX

Jan. 28, 2000 X XI

XII

Jan. 29, 2000 XIII XIV

Average

VI

-2.63

-2.63

-2.63

0.2

0.2

0.2

2.5

2.5

2.5

-2.0

-2.0

-2.0

-3.2

-3.2

-0.87

986.57

986.57

986.57

978.96

978.96

978.96

981.25

981.25

981.25

981.9

981.9

981.9

986.3

986.3

982.76

3.77

3.77

3.77

5.76

5.76

5.76

4.50

4.50

4.50

4.11

4.11

4.11

3.08

3.08

4.32

0.798

0.798

0.798

2.282

2.282

2.282

2.1

2.1

2.1

0.946

0.946

0.946

1.718

1.718

1.55

5

DO mg l-1

8.2

7.8

7.9

6.1

7.6

6.6

8.4

8.1

8.2

6.5

7.9

6.2

7.8

7.6

7.5

6 7 8 9 10

pH PO4 mg l-1 NH4 mg l-1 NO2 mg l-1 NO3 mg l-1

7.2 0.16 0.36 0.45 0.56

7.8 0.42 0.01 0.06 0.78

7.4 0.24 0.24 0.22 0.98

8.2 0.12 0.12 0.18

7.3 0.04 0.12 0.32 0.12

7.6 0.56 0.03 0.14 0.32

7.5 0.32 0.34 0.46 0.51

6.9 1.28 0.93 0.94 0.94

7.7 0.61 0.56 0.76 0.12

7.8 0.93 0.01 0.07 0.23

7.8 0.07 0.23 0.82 2.40

7.1 1.26 0.99 0.19 2.20

7.0 0.07 0.17 0.21 0.09

7.4 0.08 0.06 0.05 0.16

7.5 0.44 0.31 0.3 0.69

11

Ca mg l-1

22.6

2.1

3.1

25.0

32.0

14.3

10.5

37.5

29.0

2.5

6.4

48.5

10.2

2.2

17.6

12

Mg mg l-1 Chlorides mg l-1 Chlorophyll mg m-3 Primary Productivity mgC m-3 hr-

4.2

3.1

1.3

3.0

16.4

2.5

3.5

15.2

2.3

2.4

1.1

9.3

1.3

1.1

4.8

0.016

0.022

0.018

0.022

0.011

0.008

0.041

0.052

0.021

0.026

0.056

0.052

0.001

0.000

0.0

0.264

0.632

0.046

0.050

0.457

0.132

0.241

0.060

0.415

0.122

0.711

0.910

0.058

0.260

0.31

0.72

4.15

1.13

0.62

3.26

2.70

1.13

4.26

1.85

2.80

0.65

4.33

0.89

0.55

2.074

1.36

1.77

1.43

1.36

1.70

1.63

1.43

1.77

1.57

1.63

1.36

2.58

1.36

1.16

1.582

13 14

15

1

16

Organic Carbon %

S. No

17

18

Ecological Parameters Sediment Organism density individuals m-2 Dehydrogen ase activity μg/ g soil/24 hr

Dates and sites of the samples collected Dec. 30, 1999 Jan. 7, 2000 I II III IV V

Jan. 13, 2000 VII VIII

IX

Jan. 28, 2000 X XI

XII

Jan. 29, 2000 XIII XIV

Average

VI

1730

520

2205

1100

1115

1680

1750

1820

1050

1250

410

430

1630

380

1219

0.007

0.011

0.008

0.003

0.01

0.009

0.009

0.012

0.011

0.009

0.003

0.016

0.008

0.001

0.008

66


3.5.3. Ammonia, Phosphate, Nitrate and Nitrite Analysis for ammonia shows variation from 0.01 to 0.99 μM respectively, in different sites. Concentration ratio of PO4:NO3 ranged from 0.44 to 0.69. Ammonia in these waters probably acts as source of nitrogen for the growth of non-nitrogen fixing algal species. In surface water, nitrate is nutrient taken up by plants and assimilated into cell protein (Gajananda 2007). Maximum concentration of phosphate, ammonia, NO3 and Nitrite is found to be 1.28, 0.93, 0.94 and 0.94 mg l-1 at site no. 8 i.e. near Maitri station (table 10). An input of these nutrients seems to have taken place through anthropogenic activities (Gajananda 2007). 3.5.4. Calcium, Magnesium, Chloride Content and Chlorophyll a The average concentration of Calcium, Magnesium, Chloride, and Chlorophyll a are 17.6, 4.8, 0.0 mg l-1 and 0.31mg m-3, respectively (table 10). Calcium and magnesium dissolves out of almost all rocks and is, consequently, detected in many lakes and streams water. As it has been mention in the earlier that the SO rock comprises of metamorphic and igneous rocks, calcium and magnesium contribution to hardness of water is low. As there is no intrusion of seawater or geological formation to contribute for the chloride concentration in the lakes the average chloride content is very low (Gajananda 2007). Chlorophyll a aids in the assimilation of nutrients into cell biomass by harnessing the energy of sunlight. Its concentration is related to the quantity of the cell carbon. The concentration varies with water depth depending on the penetration of light (necessary for algal photosynthesis) and whether there is sufficient turbulence to mix the algae within the water column. Concentration of chlorophyll a (chl. a) in the surface waters in all lakes remained below 0.91 mg m-3 (Gajananda 2007). 3.5.5. Organic Carbon and Sediment Organism Density Organic carbon content of the soil samples ranged from 1.16 to 2.58 %. The soil covered with the vegetation (moss or algae) showed high organic carbon content compared to those without vegetation. The average total organic carbon content in the soil is 1.58%. Table 10. shows the result of the analysis of the soil samples collected from 14 sites of SO (Figure 1). The organic matter in the soil is contributed by the algae, lichens, mosses and the soil fauna. The greatest soil TOC content (site 12, 2.58%) is likely to be due to trampling of the microbiotic crusts through human activity, whereby a large amount of organic materials may have penetrated below ground. The average TOC content of 1.58% in the open soils of the SO, when considered against the amount of plant biomass present, can be regarded as significant in comparison with other Antarctic continental and maritime soils. The sediment organism density was found to be around 1219 individual m-2 in the SO, indicating a very low amount of fauna in the oasis (Gajananda 2003). 3.5.6. Enzyme Activity (Dehydrogenase Activity) Dehydrogenase activity (g soil-1 day-1) is an index of total soil metabolic activity and the oxidation-reduction reactions mediated by microorganisms in the soil. It is often correlated with soil fertility and even soil microbial population (Sethi et al., 1990). Also the dehydrogenase activity is dependent on the substrates availability (Schleifer et. al., 1972). The DHA values in the 14 studies sites of SO are found to be low and are about 10 times less than


67

that of marginal soils in sub-tropics (Malik et al., 1995). The DHA value shows a relationship with soil organic carbon. The low DHA in SO soils indicates that there is very limited microbial activity in the soil, which in turn, affects the decomposition process and Cmineralization. Relatively higher DHA values on the site 12 may be attributed to the inputs of the organics matter coming from the Russian Station Novolazarevskaya (Gajananda 2007).

3.6. Climatic Parameters of SO Ecosystem Weather and climate, determine to a large degree, the distribution of plants and animals, and of whole biocoenoses, not only on a continental scale but also on the regional scale. Climate governs both the distribution of plants and animals and the soil conditions, which are important for their inter-relationship. Secondly, vegetation influences both the soil and smallscale climatic conditions (the microclimate) (Stoutjesdijk and Barkman, 1991). During local summer over SO, the sun is available for 24 hours for 2 months and during this period, temperature is the highest, winds are the lowest, moisture is inducted in the form of snowfall, fog and at times by drizzle (light rain). Therefore, the most important functions of the biological life cycle took place during this period and in the later period i.e. local Antarctic winter, biological life becomes dormant. The only negative factor that prevails during summer is the high doses of UV-B radiations. Of course, our study reveals that UV-B intensity in MED/hr is negatively correlated with the productivity over SO. In fact, interaction of UV-B energy with the micro flora and fauna is still a subject of concern, which needs indepth studies. The atmospheric boundary layer (ABL), which extends from the surface to a height of about 1 km or so is the most important part for all the plants and animals to survive and is generally known as ‗biosphere‘ (Stoutjesdijk and Barkman, 1991). The ABL of Antarctica usually remains stable all round the year (Naithani and Dutta, 1995; Gajananda et. al., 2002b). Extreme stability is found in the winter months while extreme instability is reached to a lesser extent during polar summer (Naithani and Dutta 1995). Over the SO, katabatic winds, temperature, humidity, total solar radiation, UV doses, formation of inversions and cyclones etc. are the most important atmospheric parameters controlling the development of the habitats (Gajananda et. al., 2002c). Thus, considering the impact of the climate on plants and animals involved a complex factor. For instance, understanding the temperature at the surface of a plant not only need to study the air temperature, air humidity, radiation and wind, but also on the transpiration of the plant. Therefore, it is obvious that plants and animals are in interaction with their natural environment (Odum 1971). To link the ecosystem and the atmosphere it is important to study the various climatic factors such as temperature, humidity of air, winds, pressures, precipitations, evaporation rates, solar energy and UV doses etc. All these factors are discussed individually as follows:

3.6.1. Temperature Temperature plays a key role in the survival, growth, locomotory activity, life cycle, oxygen consumption rates, water balance, osmoregulatory ability, psychrophilic forms, fatty acid synthesis and other metabolic characters of plants and animal (Block et al 1994; Klok and Chown 1997; Moller and Dreyfuss 1996).

68


A perusal of the literatures shows a wide range of the effects of temperature on the flora and fauna of Antarctica. Many earlier workers had studied various aspects of temperature and their roles in determining the organisms‘ survival, evolution of super cooling ability and habitat distribution etc. Booth (1990) used various climatological data to describe the climatic requirements of plants and for numerical methods and models to indicate the decisive climatic factors for plant distribution. In another study of temperature dependences of three species of free-living Antarctic fellfield nematodes exhibited differing degrees of both strategies of cold-hardiness, freeze-tolerance and freeze-avoidance (Pickup 1990). The adaptation and acclimation of growth and photosynthesis of some Antarctic freshwater algae to low temperatures had been studied (Nagashima et al 1993; Eggert and Wiencke 2000). Both low temperature and water are limiting factors in the Antarctic terrestrial environment; these two factors have profound effect on the rate of photosynthetic response to the Antarctic moss Polytrichum alpestre to low temperatures (Kennedy 1993a-b). Franzmann (1997) found that cells of Methanogenium frigidum isolated from the perennially cold, anoxic hypolimnion of Ace Lake in the Vestfold Hills were psychrophilic, which exhibit most rapid growth at 150 C and no growth at temperatures above 18 to 200 C. The growth and consumption rates of bacteriovorous Antarctic naked marine amoebae grew at temperatures down to –20 C and showed optimal growth at 20 C and the growth efficiencies were low, typically 67%), a feature characteristic of cold tolerant higher plants (Zuñiga et al., 1996; Wasley et al., 2006). Quantifying the relative importance of lipids versus soluble carbohydrates in these freeze tolerant plants stands out as an interesting target for further study, it may be that lipids are a safer storage compound, since soluble carbohydrates are known to leak from bryophytes during desiccation-rehydration and freeze thaw cycles (Melick and Seppelt, 1992). Water is less likely to be limiting in the relatively moist Maritime Antarctic. On Signy Island, whilst some xeric species are occasionally water-limited (Davey, 1997c), more generally photosynthesis is not water-limited (Collins, 1977). When the photosynthetic rates of a range of xeric and hydric species from this Island were compared under laboratory conditions, no difference among habitats was detected (Convey, 1994). Maritime moss (A. regularis, A. depressinervis, P. alpestre, and B. algens) species from a variety of habitats (hydric, mesic, xeric) also experience increased penetration of light into the turf as drying occurs, counteracting at least in the short term the loss of productivity during periods of desiccation (Davey and Rothery, 1996). Water availability has been shown to influence turf and gametophyte morphology in a range of continental and maritime Antarctic mosses (A. regularis, P. alpestre, B. algens, Grimmia lawiana and G. antarctici) and this, in turn, can affect water relations (Nakanishi, 1979). In general, gametophyte shoots are shorter and turf denser in drier sites (Gimingham and Smith, 1971; Wasley, 2004; Wasley et al., 2006). Indeed, the changes in plant morphology and growth patterns that are reported as the norm in many long-term environmental manipulation experiments, often implicitly assumed to relate primarily to temperature increase, may equally well be explained by changes in microclimate humidity and soil moisture. In general, continental Antarctic mosses (G. lawiana, Grimmia plagiopodia, Coscinodon psudocribrosus and C. bolivianus) can survive repeated freeze-thaw events (Melick and Seppelt, 1992), whilst maritime species appears to be less tolerant (Davey, 1997b). The pattern of exposure to freezing is also important - repeated freeze-thaw cycles cause a greater reduction in gross photosynthesis than constant freezing over the same time period (Kennedy, 1993). Tolerance of freeze-thaw events involves interactions with other environmental parameters, in particular that of water availability. For example, desiccation before freezing reduces damage to the photosynthetic apparatus, while protection from freeze-thaw events can be provided by snow cover acting as an insulator (Lovelock et al., 1995a,b).

Antarctic Mosses, Limiting Factors and Their Distribution

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REFERENCES Aubert, S., Assard, N., Boutin, J. P., Frenot, Y. and Dorne, A. J.: Carbon metabolism in the subantarctic Kerguelen cabbage Pringlea antiscorbutica R. Br.: environmental controls over carbohydrates contents and relation to phenology, Plant, Cell and Environment, 22, 243-254 (1999). Bate, G. C. and Smith, V. R.: Photosynthesis and respiration in the subantarctic tussock grass Poa cookii, New Phytologist, 95, 533-543 (1983). Bednarek-Ochyra, H., Váňa, J., Ochyra, R. and Lewis Smith, R. I.: The liverwort flora of Antarctica. Polish Academy of Sciences, Cracow (2000). Bodin, K. and Nauwerck, A.: Produktionsbiologische Studien u¨ber die Moosvegetation eines Klaren Gebirgsees. Schweiz. Z. Hydrol., 30, 318-352 (1968). Cockell, C. S., Knowland, J.: Ultraviolet radiation screening compounds. Biological Review, 74, 311-345 (1999). Collins, N. J.: The growth of mosses in two contrasting communities in the maritime Antarctic: measurement and prediction of net annual production, in G.A. Llano (ed.), Adaptations within Antarctic ecosystems, Gulf Publishing, Houston, Texas, pp. 921-933 (1977). Convey, P.: Photosynthesis and dark respiration in Antarctic mosses - an initial comparative study, Polar Biology, 14, 65-69 (1994). Convey, P.: Antarctic climate change and its impacts on terrestrial ecosystems.: In: D.M. Bergstrom, P. Convey and A. H. L. Huiskes (eds), Trends in Antarctic terrestrial and limnetic ecosystems, pp. 253-272 (2006). Cooper-Drive, G. and Bhattacharya, M.: Role of phenolics in plant evolution. Phytochemistry, 49, 1165-1174 (1998). Davey, M. C.: Effects of continuous and repeated dehydration on carbon fixation by bryophytes from the maritime Antarctic, Oecologia, 110, 25-31 (1997a). Davey, M. C.: Effects of physical factors on photosynthesis by the Antarctic liverwort Marchantia berteroana, Polar Biology, 17, 219-227 (1997b). Davey, M. C.: Effects of short-term dehydration and rehydration on photosynthesis and respiration by Antarctic bryophytes, Environmental and Experimental Botany, 37, 187198 (1997c). Davey, M. C. and Rothery, P.: Seasonal variation in respiratory and photosynthetic parameters in three mosses from the maritime Antarctic, Annals of Botany, 78, 719-728 (1996). Edwards, J .A. and Smith, R. I. L.: Photosynthesis and respiration of Colobanthus quitensis and Deschampsia antarctica from the maritime Antarctic, British Antarctic Survey Bulletin, 81, 43-63 (1988). Fenton, J. H. C., and Lewis Smith, R. I.: Distribution, composition and general characteristics of the moss banks of the Maritime Antarctica, British Antarctic Survey Bulletin, 51, 215236 (1982). Gehrke, C.: Effect of enhanced UV-B radiation on production-related properties of a Sphagnum fuscum dominated subarctic bog. Functional Ecology, 12, 940-947 (1998). Gehrke, C.: Impact of enhanced ultraviolet-B radiation on mosses in a subarctc health ecosystem. Ecology, 80, 1844-185 (1999).

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Gidekel, M., Destefano-Beltran, L., Garcia, P., Mujica, L., Leal, P., Cuba, M., Fuentes, L., Bravo, L. A., Corcuera, L. J., Alberdi, M., Concha, I. and Gutiérrez, A.: Identification and characterization of three novel cold acclimation-responsive genes from the extremophile hair grass Deschampsia antarctica Desv. Extremophiles, 7, pp. 459-469 (2003). Gimingham, C. H. and Smith, R. I. L.: Growth forms and water relations of mosses in the maritime Antarctic. British Antarctic Survey Bulletin, 25, 1-21 (1971). Green, S.W.: The Antarctic moss Sarconeurum glaciale (C. Muell.) Card. and Bryhn in Southern South America. British Antarctic Survey Bulletin, 41, 187-191 (1975). Green, T., Schroeter, B. and Seppelt, R.: Effect of temperature, light and ambient UV on the photosynthesis of the moss Bryum argenteum Hedw. in continental Antarctica, in W. Davison, C. Howard-Williams and P. Broady (eds.), Antarctic ecosysystems: modes for wider ecological understanding, New Zealand Natural Sciences, Christchurch, New Zealand, pp. 165-170 (2000). Green, T. A. G., Schroeter, B. and Sancho, L. G.: Plant Life in Antarctica, in F.I. Pugnaire and F. Valladares (eds.), Handbook of functional plant ecology, Dekker, New York, U.S.A., pp. 495-543 (1999). Gwynn- Jones, D., Johanson, U., Phonix, G. K., Gehrke, C., Callaghan, T. V., Bjorn, L. O., Sonesson, M. and Lee, J. A.: UV-B impacts and interactions with other co-occuring variables of environmental change: an arctic perspective. In stratospheric Ozone Depletion. The effect of Enhanced UV-B Radiation on Terrestrial Ecosystem J. Rozema, Backhuys, Leiden, The Netherlands. pp. 187-201 (1999). Hahlbrock, K., Scheel, D.: Physiology and molecular biology of phenylpropanoid metabolism. Annu. Rev. Plant Physiol. Plant Molecular Biology, 40, 347-369 (1989). Ignatova, M. S. and Kurbatova, B.: A review of deep water bryophytes with new records from USSR. Hikobia, 10, 393-401 (1990). Imura, S., Bando, T., Seto, K., Ohtani, S., Kudoh, S., and Kanda, H.: Distribution of aquatic mosses in the Soya Coast region, East Antarctica. Polar Bioscience, 16, 1-10 (2003). Imura, S., Higuchi, M., Kanda, H. and Iwatsuki, Z.: Culture of rhizoidal tubes on an aquatic moss in the lake near Syowa Station area, Antarctica. Proc. NIPR Symp. Polar Biology, 5, 123-126 (1992). Imura, S., Bando, T., Saito, S., Seto, K. and Kanda, H.: Benthic moss pillars in Antarctic lakes. Polar Biology, 22, 137-140 (1999). Jansen, M. A. K., Gab, V., Greenberg, B. M.: Higher plants and UV-B radiation: balancing damage, repair and acclimation. Trends in Plant Science, 3, 131-135 (1998). Kanda, H.: Moss communities in some ice−free areas along the Soya Coast, East Antarctica. Memoirs of National Institute of Polar Research, Special Issue 44, 229–240 (1986). Kanda, H. and Iwatsuki, Z.: Two aquatic mosses in the lake near Syowa Station, Continental Antarctica. Hikobia, 10, 293-297 (1989). Kanda, H. and Mochida, Y.: Aquatic mosses found in lakes of the Skarvsnes region, Syowa Station area, Antarctica (Extended abstract). Proc. NIPR Symp. Polar Biology, 5, 177179 (1992). Kanda, H. and Ohtani, S.: Morphology of the aquatic mosses collected in lake Yukidori, Langhovde, Antarctica. Proc. NIPR Symp. Polar Biology, 4, 114-122 (1991). Kasper, M., Simmons, G. M., Parker, B. C., Seaburg, K. G. and Wharton, R. A.: Brryum Hedw. Collected from lake Vanda, Antarctica. Bryologist, 85, 424-430 (1982).


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Kennedy, A. D.: Water as a limiting factor in the Anatarctic Terrestrial Environment. Arctic and Alpine Research, 25, 308-315 (1993). Kubasek, W. I., Shirley, B. W., Mckilop, A., Goodman, H. M., Briggs, W., Ausubel, F. M.: Regulation of flavonoid biosynthesis genes in germinating Arabidopsis seedlings. Plant Cell, 4, 1229-1236 (1992). Lange, O. L. and Kappen, L.: Photosynthesis of lichens from Antarctica, in G.A.Llano (ed.) Antarctic Terrestrial Biology, American Geophysical Union, Washington D. C., U. S. A. pp. 83-95 (1972). Lewis Smith, R. I.: Terrestrial plant biology of the sub-antarctic and Antarctic. Antarctic ecology vol. 1 (ed. by R. M. Laws). Academic Press. London. pp. 61-162 (1984). Light, J. J. and Heywood, R. B.: Deep-water moss in Antarctic lakes. Nature, 242, 535-536 (1973). Light, J. J. and Heywood, R. B.: Is the vegetation of continental Antarctica predominantaly aquatic? Nature, 256, 199-200 (1975). Light, J. J. and Smith, R. I. L.: Deep water bryophytes from the highest schottish lochs. Bryology, 9, 55-62 (1976). Longton, R. E.: Microclimate and biomass in communities of the Bryum association on Ross Island, continental Antarctica. The Bryologist, 77, 109-127 (1974). Longton, R. E.: The biology of polar bryophytes and lichen. New York, Cambridge University Press, pp. 391 (1988). Lovelock, C. E., Jackson, A. E., Melick, D. R. and Seppelt, R. D.: Reversible photoinhibition in Antarctic moss during freezing and thawing. Plant Physiology, 109, 955-961 (1995a). Lovelock, C. E., Osmond, C. B. and Seppelt, R. D.: Photoinhibition in the Antarctic moss Grimmia antarctici Card when exposed to cycles of freezing and thawing. Plant Cell and Environment, 18, 1395-1402 (1995b). Lyons, W. B., Howard-Williams, C. and Hawes, I. (eds): Ecosystem processes in Antarctic ice-free landscapes. Balkema, Rotterdam, XII, 1-281 (1997). Markham, K.: Bryophyte flavonoids, their structure, distribution, and evolutionary significance. In Bryophytes: their Chemistry and Chemical Taxonomy (eds H. Zinsmeister and R. Mues). Oxford University Press, Oxford. pp. 143-159 (1990). Matteri, C. M.: Patagonia bryophytes 6. Fruiting Sarconeurum glaciale (C. Muell.) Card. Et Bryhn newly found in sothern Patagonia. Lindbergia, 8, 105-109 (1982). Melick, D. R. and Seppelt, R. D.: Loss of soluble carbohydrates and changes in freezing point of Antarctic bryophytes after leaching and repeated freeze-thaw cycles. Antarctic Science, 4, 399-404 (1992). Melick, D. R. and Seppelt, R. D.: Seasonal investigations of soluble carbohydrates and pigment levels in Antarctic bryophyte and lichens. The Bryologist, 97, 13-19 (1994). Nakanishi, S.: Ecological studies of the moss and lichen communities in the ice free areas near Syowa Station, Antarctica. Nankyoku Shiryo. Antarctic Record, 59, 68-96 (1977). Nakanishi, S.: On the variation of leaf characters of an Antarctic moss, Bryum inconnexum. Memoirs of the National Institute of Polar Research, 47-57 (1979). Nimi, R., Martikainen, P., Silvola, J. et al.: Responces of two Sphagnum moss species and Eriophorum vaginatum to enhanced UV-B in a summer of low UV intensity. New Phytologist, 156, 509-515 (2002a).

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Nimi, R., Martikainen, P., Silvola, J. et al.: Elevated UV-B radiation 680 alters fluxes of methane and carbon dioxide in peatland microcosms. Global Change Biology, 8, 361-371 (2002b). Ochi, H.: A taxonomic review of the genus Bryum Musci in the Antarctica. Memoirs of the National Institute of Polar Research. Spec. Issue, 11, 70-80 (1979). Ochyra R.: The moss flora of King George Island, Antarctica. Polish Academy of Sciences,W. Szafer Institute of Botany, Cracow, i-xxiv, 1-278 (1998). Olsson, L. C., Veit, M., Weissenbok, G., Bornman, J. F.: Differential flavonoid response to enhanced UV-B radiation in Brassica napus. Phytochemistry, 49: 1021-1028 (1998). Pannewitz, S., Schlensog, M., Green, T.G.A., Sancho, L. and Schroeter, B.: Are lichens active under snow in continental Antarctica? Oecologia 135, 30-38 (2003). Priddle, J.: Morphology and adaptation of aquatic mosses in the Antarctic lake. Bryology, 10, 517-529 (1979). Priddle, J. and Dartmall, H. J. G.: The biology of an Antarctic aquatic moss community. Freshwater Biology, 8, 469-480 (1978). Putzke, K., and Pereira, A. B.: The Antarctic mosses, with special reference to the south Shetland Island. Universidade Luterana do Brasil, ISSBN 85-7528-008-2 (2001). Rastorfer, J. R.: Comparative physiology of four west Antarctic mosses. Antarctic Research Series, 20, 143-161 (1972). Robinson, S. A., Turnbull, J. D. and Lovelock C. E.: Impact of changes in natural ultraviolet radiation on pigment composition, physiological and morphological characteristics of the Antarctic moss, Grammia antarctici. Global Change Biology, 11, 476-489 (2005). Robinson, S. A., Wasley, J., Popp, M. and Lovelock, C. E.: Desiccation tolerance of three moss species from continental Antarctica. Australian Journal of Plant Physiology, 27, 379-388 (2000). Robson, T. M., Pancotto, V. A., Flint, S. D. et al.: Six years of solar UV-B manipulations affect growth of sphagnum and vascular plants in a tierra del fuego peatland. New Phytologist, 160, 379-389 (2003). Savich-Lyubitskaya, L. I. and Smirnova, Z. N.: New species of Bryum Hedw. From the Bunger Hills. Inf. Byull. Sov. Antarkt. Eksped., 7, 34-39 (1959). Savich-Lyubitskaya, L. I. and Smirnova, Z. N. New variety of Bryum korotkevicziae Sav.Lyub. et Z. Smirn. Inf. Byull. Sov. Antarkt. Eksped., 17, 25-27 (1960). Savich-Lyubitskaya, L. I. and Smirnova, Z. N.: A deep water member of the genus Plagiothecium Br. et Sch. In Antarctica. Inf. Byull. Sov. Antarkt. Exped., 49, 33-39 (1964). Schroeter, B., Kappen, L., Green, T. G. A. and Seppelt, R. D.: Lichens and the Antarctic environment: Effects of temperature and water availability on photosynthesis, in W.B. Lyons, C. Howard-Williams and I. Hawes (eds.), Ecosystem processes in Antarctic icefree landscapes. Balkema, Rotterdam, The Netherlands. pp. 103-118 (1997). Searles, P., Flint, S. Diaz, S. B. et al.: Solar ultraviolet-B radiation 705 radiation influence on Sphagnum bog and Carex fen ecosystem: first field season findings in Tierra del Fuego, Argentina. Global Change Biology, 5, 225-234 (1999). Searles, P., Flint, S. Diaz, S. B. et al.: Plant response to solar ultraviolet-B radiation in a southern South American Sphagnum peatland. Journal of Ecology, 90, 704-713 (2002).


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Chapter 7

AFFINITIES OF LICHEN FLORA OF INDIAN SUBCONTINENT VIS-À-VIS ANTARCTIC AND SCHIRMACHER OASIS Dalip K. Upreti* and Sanjeeva Nayaka ABSTRACT Affinities of Indian subcontinent lichen flora with lichens of Antarctic and Schirmacher Oasis are discussed in detail. Out of 439 taxa of lichens known from the Antarctica and South Georgia 76 are similar to Indian subcontinent and 68 with the Schirmacher Oasis, while 18 species are common in both subcontinent and Schirmacher Oasis. The genus Cladonia with 17 species showed the maximum affinities of Antarctic lichens. Most of the Indian subcontinent lichens which exhibited affinities with Antarctica are known mostly from temperate and alpine regions of the subcontinent.

Keywords: Diversity, distribution, similarity, geographical isolation, speciation.

INTRODUCTION Lichens are one of the most widely distributed groups of organisms in the world; exhibit their presence in almost all the habitats available. They have an ability to grow on rock, stones, bark, leaves and various man made substrates including glass plane, iron rods and plastics. The dry and sterile rock surfaces where other group of plants unable to grow, but lichens colonizes successfully on them and flourish. Lichens exhibit broadest range of habitats as they occur both in dry hot and cold desert, from low sea level region to highest mountains. *

Email: [email protected], Mobile: +919450400264 Lichenology Laboratory, National Botanical Research Institute (NBRI-CSIR), Rana Pratap Marg, Lucknow – 226001, U.P., India

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The Antarctic regions is a well known extreme environment for plant life, as the temperatures are low, there are long periods of frost and snow cover and frequent winds that causes abrasion and evaporation. Lichens, because of their high resistance to freezing and their ability to endure long periods of inactivity in a frozen state, can survive in this environment (Kappen 1973). In the past few decades a large number of lichenological investigations on Antarctic lichens were carried out in different regions of the world, thus resulted a fairly clear picture of the diversity and distribution of lichens in the region. Øvstedal and Smith (2001) provided the detailed diversity and biogeography of the lichen biota in Antarctica. Accordingly, South Georgia which is represented by 194 species of lichen has 47 exclusive species not known from Antarctic biome. The Antarctic Peninsula has greatest diversity of 268 taxa. The South Orkeys and South Shethland Islands are represented by 221 and 211 taxa.

MATERIALS AND METHODS The enumeration of lichens known from different regions of Antarctica and Schirmacher Oasis (SO), East Antarctica are compiled from the investigation provided by Lindsay (1977) and Øvstedal and Smith (2001). The inventory of Indian subcontinent lichens provided by Awasthi (2000) was used for tracing out the affinities of subcontinent lichens with Antarctic lichens. All the information available on lichens of SO in the last five decades is consolidated in Table 1, while Table 2. enumerates the affinities of lichens occurring in Antarctica, Indian subcontinent and SO. Table 1. Occurrence of lichens in Schirmacher Oasis, E. Antarctica (Cr = Crustose, Fo = Foliose, Fr = Fruticose, En = Endemic, Bi = Bipolar, Co = Cosmopolitan) Lichen taxa 1 2 3 4 5

6

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Growth Form Acarospora. flavocordia Castello and Nimis Cr Cr A. gwynnii C.W. Dodge and E.D. Rudolph Cr A. macrocyclos Vain. Cr A. williamsii Filson Amandinea coniops (Wahlenb.) M. Choisy ex Cr Scheid. - Lecidea coniops Wahenb. - Buellia coniops (Wahlenb.) Th. Fr. A. petermannii (Hue) Matzer, H. Mayerhofer Cr and Scheid. - Lecanora petermanii Hue - Rinodina petermanii (Hue) Darb. - Beltraminia petermannii (Hue) C.W. Dodge A. punctata (Hoffm.) Coppins and Scheid. Cr - Lecidea punctata Hoffm. - Buellia punctata (Hoffm.) A. Massal.

Distribution En En En En Bi

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En

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-

Co

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10 11 12 13 14 15 16 17 18 19

20 21 22 23

24 25 26

27 28

29 30

31

Growth Form Cr

Arthonia molendoi (Frauenf.) R. Sant. - Tichothecium molendoi Frauenf. A. rufidula (Hue) D. Hawksw., R. Sant. and Cr Øvstedal - Charcotia rufidula Hue Cr Bacidia johnstonii C.W. Dodge Cr B. stipata I.M. Lamb Cr Buellia darbishirei I.M. Lamb B. frigida Darb. Cr Cr B. grimmiae Filson Cr B. grisea C.W. Dodge and G.E. Baker Cr B. illaetabilis I.M. Lamb. Cr B. lingonoides R. Filson B. pallida Dodge and Baker Cr Cr B. papillata (Sommerf.) Tuck. - Lecidea papillata Sommerf. - Tetramelas papillatus (Sommerf.) Kalb. B. pycnogonoides C.W. Dodge and G.E. Baker Cr Cr B. subfrigida May. Inoue Cr Caloplaca athallina Darb. C. citrina (Hoffm.) Th. Fr. Cr - Verrucaria citrina Hoffm. - Pyrenodesmia mawsonii C.W. Dodge Cr C. frigida Søchting Cr C. lewis-smithii Søchting and Øvstedal C. saxicola (Hoffm.) Nordin Cr - Psora saxicola Hoffm. - Gasparrinia murorum Tornab. Fo Candelaria murrayi Poelt Candelariella flava (C.W. Dodge and G.E. Cr Baker) Castello and Nimis - Huea flava C.W. Dodge and G.E. Baker - C. antarctica R. Filson - C. hallettensis (J.S. Murray) Øvestedal - Protoblastenia citrina C.W. Dodge Cr Carbonea assentiens (Nyl.) Hertel - Lecidea assentiens Nyl. Cr C. vorticosa (Flörke) Hertel - Lecidea sabuletorum var. vorticosa Flörke - L. vorticosa (Flörke) Körb. - L. capsulata C.W. Dodge and G.E. Baker - C. capsulata (C.W. Dodge and G.E. Baker) Hale Cr Lecania cf. racovitzae (Vain.) Darb.

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Distribution Bi

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En

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+

En En En En En En En En En Bi

+ + + + + -

+ + + + + + + + +

En En En Co

+ +

+ + + +

En En Bi

+

+ + +

En En

+

+ +

En

+

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Dalip K. Upreti and Sanjeeva Nayaka Table 1. (Continued) Lichen taxa

- Lecanora. racovitzae Vain. 32 Lecanora epibryon (Ach.) Ach. - Lichen epibryon Ach. - L. broccha Nyl. 33 L. expectans Darb. 34 L. fuscobrunnea C.W. Dodge and G.E. Baker 35 L. geophila (Th. Fr.) Poelt - Placodium geophillum Räsänen 36 L. cf. mawsonii C.W. Dodge 37 L. mons-nivis Darb. 38 L. orosthea (Ach.) Ach. - Lichen orostheus Ach. 39 L. polytropa (Hoffm.) Rabenh. - Verrucaria polytropa Ehrh. 40 L. sverdrupiana Øvstedal 41 Lecidea andersonii Filson 42 L. auriculata Th. Fr. 43 L. cancriformis C.W. Doge and G.E. Baker - L. phillipsiana R. Filson 44 L. lapicida (Ach.) Ach. - L. lapicida Ach. - L. rupicida Vain. 45 L. cf. placodiiformis Hue 46 Lecidella siplei (C.W. Dodge and G.E. Baker) May Inoue - Lecidea siplei C.W. Dodge and G.E. Baker 47 L. stigmatea (Ach.) Hertel and Leuckret - L. stigmatea Ach. 48 Lepraria cacuminum (A. Massal.) Kümmerl. and Leuckert - Diploicia cacuminum A. Massal. 49 L. neglecta (Nyl.) Erichs. - Lecidea neglecta Nyl. 50 Physcia caesia (Hoffm.) Furner. - Lichen caesius Hoffm. - P. wainioi Räsänen 51 P. dubia (Hoffm.) Lettau - Lobaria dubia Hoffm. 52 Pleopsidium chlorophanum (Wahlenb.) Zopf. - Parmelia chlorophana Wahlenb. - Acarospora chlorophana (Wahlen.) Mass. - Biaterella antarctica J.S. Murray - B. cerebriformis (C.W. Dodge) R. Filson 53 Pseudephebe minuscula (Nyl. Ex Arnold) Brodo and Hawks. - Imbricaria lanata var. minuscula Arnold

Growth Distri- Nayaka Olech and Form bution et al 2009 Singh 2010 Cr

Bi

+

-

Cr Cr Cr

En En Bi

+ + +

+ + +

Cr Cr Cr

En En Bi

+

+ + +

Cr

Bi

+

-

Cr Cr Cr Cr

En En Co En

+ + +

+ + +

Cr

Co

+

-

Cr Cr

En En

+

+ +

Cr

Bi

+

+

Cr

Co

+

+

Cr

Bi

+

-

Fo

Co

+

+

Fo

Co

+

+

Cr

Bi

+

+

Fr

Bi

+

+

Affinities of Lichen Flora of Indian Subcontinent… Lichen taxa

153

Growth Distri- Nayaka Olech and Form bution et al 2009 Singh 2010

- Parmelia minuscule (Nyl. ex Arnold) Nyl. 54 Rhizocarpon geminatum Körb. Cr 55 R. geograhicium (L.) DC Cr - Lichen geographicus L. - R. flavum C.W. Doge and G.E. Baker 56 R. nidificum (Hue) Darb. Cr - Lecidea nidifica Hue 57 Rhizoplaca melanophthalma (Ram.) Leuckert and Cr Poelt - Squamaria melanophthalma Ram. - L. melanophthalma (Ram.) Ram. 58 Rinodina endophragmia I.M. Lamb. Cr 59 R. olivaceobrunnea C.W. Dodge and G.E. Baker Cr 60 Sarcogyne privigna (Ach.) A. Massal Cr - Lecidea privigna Ach. 61 Umbilicaria africana (Jatta) Krog and Swinscow Fo - Gyrophora caplocarpa var. africana Jatta 62 U. antarctica Frey and I.M. Lamb Fo 63 U. aprina Nyl. Fo - Omphalodiscus spongiosus (C.W. Dodge and G.E. Baker) Llano var. subvirginis (Lamb et Frey) Golubk. 64 U. decussata (Vill.) Zahlbr. Fo - Lichen decussatus Vill. - Omphalodiscus decussatus (Vill.) Schol. var. discolor Lynge 65 U. vellea (L.) Ach. Fo - L. velleus L. 66 Usnea antarctica Du. Rietz Fr 67 U. sphacelata R. Br. Fr - U. sulphrea Th. Fr. 68 Xanthoria elegans (Link) Th. Fr. Fo - Lichen elegans Link - Gasparrinia elegans Stein apud Cohn 69 X. mawsonii Dodge Fo

Bi Co

+

+ +

En

+

-

Bi

+

+

Bi Bi Co

+ + +

+ + +

Co

+

+

En Co

+ +

+ +

Bi

+

+

Co

+

-

Co Bi

+ +

+ -

Co

+

+

En

+

+

Table 2. Affinities of Antarctic lichens with Indian subcontinent lichen flora and lichens of SO S. No. 1 2 3 4 5

Antarctica Acarospora badiofusca (Nyl.) Th. Fr. A. flavocordia Castello and Nimis A. gwynnii C.W. Dodge and E.D. Rudolph A. macrocyclos Vain. A. williamsii Filson

India + -

SO + + + +

154

Dalip K. Upreti and Sanjeeva Nayaka Table 2. (Continued)

S. No. 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Antarctica Amandinea coniops (Wahlenb.) M. Choisy ex Scheid. A. petermannii (Hue) Matzer, H. Mayerhofer and Scheid. A. punctata (Hoffm.) Coppins and Scheid. Arthorhaphis alpina (Schaer.) R. Sant. Arthonia molendoi (Frauenf.) R. Sant. A. rufidula (Hue) D. Hawksw., R. Sant. and Øvstedal Bacidia johnstonii C.W. Dodge B. stipata I.M. Lamb Bryonora castanea (Hepp) Poelt Buellia darbishirei I.M. Lamb B. frigida Darb. B. grimmiae Filson B. grisea C.W. Dodge and G.E. Baker B. illaetabilis I.M. Lamb. B. lingonoides R. Filson B. pallida Dodge and Baker B. papillata (Sommerf.) Tuck. B. pycnogonoides C.W. Dodge and G.E. Baker B. subfrigida May. Inoue Caloplaca athallina Darb. C. cerina (Ehrh. ex Hedw.) Th. Fr. C. citrina (Hoffm.) Th. Fr. C. exsecuta (Nyl.) Dalla Torre C. holocarpa (Hoffm.) Wade C. frigida Søchting C. lewis-smithii Søchting and Øvstedal C. saxicola (Hoffm.) Nordin Candelaria murrayi Poelt Candelariella aurella (Hoffm.) Zahlbr. C. flava (C.W. Dodge and G.E. Baker) Castello and Nimis C. vitellina (Ehrh.) Müll. Arg. Carbonea assentiens (Nyl.) Hertel C. vorticosa (Flörke) Hertel Cetraria aculeata (Schreb.) Fr. C. islandica (L.) Ach. Chrysothrix chlorina (Ach.) J.R. Laundon Cladia aggregate (Sw.) Nyl. Cladonia bellidiflora (Ach.) Schaer C. carneola (Fr.) Fr. C. chlorophaea (Flörke ex Sommerf.) Spreng. C. deformis (L.) Hoffm. C. fimbriata (L.) Fr. C. galindezii Øvstedal

India + + + + + + + + + + + + + + + + + + + + + +

SO + + + + + + + + + + + + + + + + + + + + + + + + + + + -

Affinities of Lichen Flora of Indian Subcontinent… S. No. 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93

Antarctica C. gracilis (L.) Wild. C. mitis Sandst. C. phyllophora Hoffm. C. pleurota (Flörke) Schaer. C. pocillum (Ach.) O.J. Rich. C. pyxidata (L.) Hoffm. C. rangiferina (L.) Webber C. scabriuscula (Delise) Nyl. C. squamosa (Scop.) Hoffm. C. subsubulata Nyl. Collema tenax (Sw.) Nyl. Lecania racovitzae (Vain.) Darb. Lecanora epibryon (Ach.) Ach. L. expectans Darb. L. frustulosa (Dicks.) Ach. L. fuscobrunnea C.W. Dodge and G.E. Baker L. geophila (Th. Fr.) Poelt L. mawsonii C.W. Dodge L. mons-nivis Darb. L. orosthea (Ach.) Ach. L. polytropa (Hoffm.) Rabenh. L. sverdrupiana Øvstedal Lecidea andersonii Filson L. atrobrunnea (Ramond) Schaer. L. auriculata Th. Fr. L. cancriformis C.W. Doge and G.E. Baker L. lapicida (Ach.) Ach. L. placodiiformis Hue Lecidella elaeochroma (Ach.) M. Choisy L. siplei (C.W. Dodge and G.E. Baker) May Inoue L. stigmatea (Ach.) Hertel and Leuckret Lecidoma demissum (Rutstr.) Gotth. Schneid. and Hertel Lepraria cacuminum (A. Massal.) Kümmerl. and Leuckert L. neglecta (Nyl.) Erichs. Leproloma vouaux (Hue) J.R. Laundon Megaspora verrucosa (Ach.) Hafellner and V. Writh Ochrolechia tartarea (L.) A. Massal. Parmelia saxatilis (L.) Ach. P. sulcata Taylor Peltigera didactyla (With.) J.R. Laundon P. rufescens (Weis) Humb. Pertusaria coccodes (Ach.) Nyl. Phaeophyscia endococcina (Körb.) Moberg Phaeorrhiza nimbosa (Fr.) H. Mayrhofer and Poelt Physcia caesia (Hoffm.) Furner.

155 India + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

SO + + + + + + + + + + + + + + + + + + + +

156

Dalip K. Upreti and Sanjeeva Nayaka Table 2. (Continued)

S. No. 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126

Antarctica P. dubia (Hoffm.) Lettau Physconia muscigena (Ach.) Poelt Placynthiella icamalea (Ach.) Coppins and P. James Pleopsidium chlorophanum (Wahlenb.) Zopf. Protoparmelia badia (Hoffm.) Hafellner Pseudephebe minuscula (Nyl. Ex Arnold) Brodo and Hawks. Psilolechia lucida (Ach.) M. Choisy Rhizocarpon badioatrum (Flörke ex Spreng.) Th. Fr. R. disporum (Hepp) Müll. Arg. R. geminatum Körb. R. geograhicium (L.) DC R. nidificum (Hue) Darb. R. superficiale (Schaer.) Malme Rhizoplaca melanophthalma (Ram.) Leuckert and Poelt Rinodina endophragmia I.M. Lamb. R. olivaceobrunnea C.W. Dodge and G.E. Baker Sarcogyne privigna (Ach.) A. Massal Sporastatia testudinea (Ach.) A. Massal. Stereocaulon alpinum Laurer Tephromela atra (Huds.) Hafellner ex Kalb Umbilicaria africana (Jatta) Krog and Swinscow U. antarctica Frey and I.M. Lamb U. aprina Nyl. U. decussata (Vill.) Zahlbr. U. krascheninnikovii (Savicz) Zahlbr. U. thamnodes Hue Usnea antarctica Du. Rietz U. sphacelata R. Br. Verrucaria maura Wahlenb. in Ach. V. muralis Ach. Xanthoria candelaria (L.) Th. Fr. X. elegans (Link) Th. Fr. X. mawsonii Dodge

India + + + + + + + + + + + + + + + + + + + + + + + -

SO + + + + + + + + + + + + + + + + +

RESULTS AND DISCUSSION Distribution Pattern of Antarctic Lichens The Antarctic lichens exhibit four categories of their distributional pattern (Rudolph 1967). 1. The Antarctic Peninsula (west coast): Usnea fasciata and Ramalina terebrata shows their similar pattern of distribution in west coast comprising of Antarctic Peninsula,

Affinities of Lichen Flora of Indian Subcontinent…

157

South Shetland, South Georgia and outlying of Falkland Islands. Some members of the stipitate and crustose members of lichens also exhibit their restricted distribution in the west coast of the Antarctic Peninsula, South Shetland and South Orkney Islands are Bacidia stipitata, Catilaria corymbosa, Caloplaca regalis, Lecania brialmontii and Rinodina petermanii. The Antarctic Peninsula (west coast) exhibit occurrence of distinctive elements such as Cladonia rangiferina, Cornicularia aculenta, Cystocoleus niger, Himantormia lugubris, Massalengia cornosa, Pannaria hookeri, Parmelia gerlachei, P. ushuaiensis, Pseudophebe pubescens, Sphaerophorus globosus and Stereocaulon glabrum. Most of the species under this category exhibit a strong maritime tendency. 2. The Antarctic Peninsula (east coast): The Antarctic Peninsula possesses a continuous mountainous range of altitudinal variation of 1500 – 2500 m in height. Due to the height of the mountain range the climate divide between two coasts. The west coast has a strong maritime climate with relatively warm, wet winds but the east coast having extensive ice shelf provide a relatively cold, dry winds approaching that of continental Antarctica. Usnea sulphurea and U. fasciata dominates the area. Pseudophebe minuscule also occur in this region. 3. The Antarctic Peninsula Endemic: The stipitate crustose lichen species such as Bacidia stipata, Catilaria corymbosa, Caloplaca regalis, Lecania brialmontii and Rinodina petermanii are restricted to the west coast of the Antarctic Peninsula and South Shetland and South Orkeney Islands and have originated in this region (Lindsay 1975). 4. The Circumpolar Antarctic: Buellia frigida an endemic species of Antarctica and Xanthoria elegans a circumpolar species exhibit their scattered occurrence in this category. Though the Arctic and Antarctic lichens exhibit many similarities in their origins, however, the restricted nature of Antarctic lichen flora show little similarity with the Arctic. Out of the 45 genera of lichens known from the Arctic 20 are also known from the Antarctic. Out of 328 species of lichens recorded from Greenland (Lynge 1937), 47 are found in the Antarctic, while out of the 65 genera listed from the former region 46 are found in the later. The greater number of genera in common between Arctic and Antarctic supports the idea that at one time the polar lichen floras were basically similar, but the geographical isolation, especially that of Antarctica from other southern hemisphere continents, has led to differences through speciation.

Lichen Flora of Schirmacher Oasis, East Antarctica SO is a small ice-free landmass of 35 km2, located in Queen (Dronning) Maud Land area of continental east Antarctica (70.8° S and 11.8° E) and is surrounded by 10 nunataks (Figure 1). Lichens from SO have been collected since the year 1970s and Golubkhova and Simonov (1972) published the first comprehensive list of 21 lichen taxa form the area. Ritcher (1990) provided a list of 25 species of lichens collected by the Russian researchers from this area between the year 1979 and 1984. Further, Ritcher (1995) published a revised list of lichens comprising 26 species including the specimen collected during 1988-89.

158


Figure 1. Map showing the location of Schirmacher Oasis and surrounding nunataks.

The National Botanical Research Institute (NBRI-CSIR) Lucknow, was identified by the Ministry of Earth Science, New Delhi as the centre for carrying out lichenological studies in SO in the year 1991. The organization participated for the first time in the 11th Indian Antarctic Expedition (IAE) during the year 1991-92 and reported a total of 26 lichen species (Upreti and Pant 1995, Upreti 1996, 1997). During 17th IAE Pandey and Upreti (2000) listed a total of 19 lichen species collected from the SO and the Vettiya nunatak. Mean while Gupta et al. (1999) of the Botanical Survey of India also collected some lichens form SO during 18th IAE and reported five more species. NBRI continued its participation in the 22nd IAE and more extensively and intensively explored the 31 sites of the whole stretch of SO together with seven nunataks located nearby and listed a total of 35 lichen species (Nayaka and Upreti 2005). The consolidation of published accounts on the SO lichens revealed the occurrence of total of 48 species in the area (Nayaka et al. 2009). Out of the 48 lichen species that occur in SO, 19 are cosmopolitan in distribution. Olech and Singh (2010) during 23rd IAE in 2003-04 made a detailed lichenological survey of the Oasis and reported 57 lichen taxa after adding 22 new addition to the Oasis. The consolidation of all the available lichenological studies revealed the occurrence of 69 species in the SO (Table 1). The species of lichen genus Buellia dominates the area with 10 species, followed by 9 species of Lecanora, 5 species each of Caloplaca and Umbilicaria. The crust forming species dominates the area with 54 species, while only 9 species are foliose, 4 are fruticose and single species of leprose form.

Affinities of Indian Lichen Flora with Lichens of SO and Antarctica Awasthi (2000) listed 2450 species of lichens from the Indian subcontinent. Most of the macrolichens (foliose and fruticose) are more or less fairly well worked out from India. However, some of the microliches (leprose, crustose and squamulose) are still in need of revisionary studies based on the modern concept of different lichen taxa available. In the last few decades a large number of microlichens from India are studied in detail and on the basis of their occurrence and distributional pattern, tentative observations can be made in respect of


159

the affinities of the lichen flora of the subcontinent with neighbouring area and other regions including Antarctica. A large number of lichen species of the subcontinent are cosmopolitan in distribution. The eastern Himalayan lichen flora has many species common with the SinoJapanese and south-east Asian regions. Lichen species present in the western Himalayas exhibit a distinct affinity with the lichen flora of northern Europe. Though the Antarctic lichen flora exhibits a more restricted nature, however most of the lichen genera are known from Antarctica is also exhibit their occurrence in other regions of the world including Indian subcontinent. The SO is represented by the following 23 genera of lichens; Acarospora, Amandinea, Arthonia, Bacidia, Buellia, Caloplaca, Candelaria, Carbonea, Lecania, Lecanora, Lecidea, Lecidella, Lepraria, Physcia, Pleopsidium, Pseudophebe, Rhizocarpon, Rahizoplaca, Rinodina, Sarcogyna, Umbilicaria, Usnea and Xanthoria. Except the genus Pseudophebe all the 22 genera know from SO are also know from India and the Indian subcontinent. Out of the 69 species, so far known from SO, 19 species belonging to 13 genera are also known from India. The lichen taxa common between India and SO are Amandinea punctata, Caloplaca cerina, C. citrina, C. frigida, C. saxicola, Carbonea vorticosa, Lecanora polytropa, Lecidea auriculata, L. lapicida. Lecidella stigmatea, Physcia caesia, P. dubia, Pleopsidium chlorphanum, Rhizocarpon geographicum, Rhizoplaca melanophthalma, Sarcogyne privigna, Umbilicaria decussata, U. vellea and Xanthoria elegans. In India most of the lichen species which exhibit their occurrence in SO are mostly exhibit their restricted distribution in temperate and alpine regions of the Himalayas. Rhizocaron geographicum sometimes also found growing on rocks in higher altitudes of southern Indian region. Out of 439 taxa of lichens so far known from Antarctica and South Georgia (Øvstedal and Smith 2001, 2004) 76 species exhibit similarities with Indian subcontinent and 68 with the SO. Out of 76 Indian subcontinent lichen species common to Antarctica (Figure 2) the lichen genus Cladonia is represented by 64 species in the subcontinent, out of which 17 (47%) species are also known to occur in Antarctica. However, the SO is devoid of this genus as not a single species of Cladonia is known from there.

Lecidea 5%

Lecidella 5%

Parmelia 5%

Physcia 5% Xanthoria 5%

Caloplaca 12%

Cladonia 47%

Rhizocarpon 8% Umbilicaria 8%

Figure 2. Representation of some major Indian subcontinent lichens in Antarctica.

160


The species of Phaeophyscia, Physcia and Physconia are widely distributed in Indian Himalayan regions are also known from Antarctica, while except for Physcia other two genera do not exhibit their representation in SO. Most of Indian species of Rhizocarpon show affinities to the Antarctic lichens as 5 species are commonly known from both the regions. It is interesting to note that Buellia, a crustose thalloid genus, most common in Antarctica and Indian subcontinent have different species, but not a single species of Antarctica occur in India. However, SO is represented 10 species of Buellia known from Antarctica. Most of the genera of lichens known from India are also reported from Antarctica. The greater number of genera is common between Indian subcontinent and Antarctica supports the idea that one time the Indian subcontinent and Antarctic lichen flora were basically similar, but the geographical isolation that of Antarctica from other southern hemisphere continents has led to difference through speciation.

ACKNOWLEDGMENTS We thank Director, National Botanical Research Institute, Lucknow for providing laboratory facilities, Ministry of Earth Science and Council of Scientific and Industrial Research, New Delhi for facilitating Antarctic expeditions.

REFERENCES Awasthi, D.D.: Lichenology in Indian Subcontinent. Bishen Singh Mahendra Pal Singh, Dehra Dun (2000). Golubkova, N.S. and I.M. Simonov: Lishayniki Oazisa Shirmakhera. Trudy Sovet Skoy East Antarkti Cheskoy Eksfeditsii Leningrad, 60, 317-327 (1972). Gupta, B.K., G.P. Sinha, and D.K. Singh: A note on lichens of Schirmacher Oasis, East Antarctica. Indian J. Forestry., 22(3), 292-294 (1999). Kappen, L.: Response to extreme environments. In: The lichens (Eds: V. Ahmadjian and M.E. Hale). Academic Press, New York. pp 311-380 (1973). Lindsay, D.C.: Lichens of cold deserts. In: Lichen Ecology (Eds: M.R.D. Seaward.). Academic Press, London. pp. 183-209 (1977). Lindsay, D.C.: The macrolichens of South Georgia. Brit. Antarct. Surv. Sci. Rep., 89, 1-91 (1975). Lynge, B.: Lichens from West Greenland, collected chiefly by Th. M. Fries. Meddr. Grønland., 118, 1-225 (1937). Nayaka, S. and D.K. Upreti: Schirmacher Oasis, East Antarctic, a lichenologically interesting region. Curr. Sci., 89(7), 1059-1060 (2005). Nayaka, S., D.K. Upreti and R. Bajpai: Diversity and adaptive response of lichens in Antarctica with special reference to Schirmacher Oasis. In: Frontiers in Fungal Ecology, Diversity and Metabolites (Ed. K.R. Sridhar.). I.K. Internataional Publishing House Pvt. Ltd., New Delhi. pp. 107-123 (2009). Olech, M. and S.M. Singh: Lichens and Lichenicolous Fungi of Schirmacher Oasis, Antarctica. National Centre for Antarctic and Ocean Research, Vasco da Gama (2010).


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Øvstedal, D.O. and R.I.L. Smith: Addition and corrections to the lichens of Antarctica and South Georgia. Cryptogamie Mycologie. 25(4), 323-331 (2004). Øvstedal, D.O. and R.I.L. Smith: Lichens of Antarctica and South Georgia. A guide to their identification and ecology. Cambridge University Press, U.K. (2001). Pandey, V. and D.K. Upreti: Lichen flora of Schirmacher Oasis and Vettiyya Nunatak. In: Scientific Report: Seventeenth Indian Expedition to Antarctica. Ministry of Earth Science, New Delhi. Technical Publication No. 15. pp. 185-201 (2000). Ritcher, W.: Biology. In: The Schirmacher Oasis, Queen Maud Land, East Antarctica and its surroundings (Eds: P. Bormann and D. Fritzsche.). Germany. 321-347 (1995). Ritcher, W.: The lichens of the Schirmacher Oasis (East Antarctica). Geodätische und Geophysikalische Veröffentlichungen, Reihe 1, Berlin 16, 471-488 (1990). Rudolph, E.D.: Lichen distribution. In: Terrestrial Life in Antarctica (Eds: V. Bushnell). Antarct. Map Fol. Ser., 5, 9-11 (1967). Upreti, D.K. and G. Pant: Lichen flora in and around Maitri region, Schirmacher Oasis, East Antarctica. In: Scientific Report: Eleventh Indian Expedition to Antarctica. Ministry of Earth Science, New Delhi. Technical Publication No. 9, pp. 229-241 (1995). Upreti, D.K.: Lecideoid lichens from the Schirmacher Oasis, East Antarctica. Willdenowia., 25, 681-686 (1996). Upreti, D.K.: Notes on some crustose lichens from Schirmacher Oasis, East Antarctica. Feddes Repertorium., 108(3-4), 281-286 (1997).


Chapter 8

WATER RELATION OF SOME COMMON LICHENS OCCURRING IN SCHIRMACHER OASIS, E. ANTARCTICA Sanjeeva Nayaka1 *, Dalip K. Upreti1 and Ruchi Singh2 ABSTRACT The lichens are classic examples of poikilohydric desiccation tolerant organisms. The existence of lichens in Antarctica is mainly due to their morpho-physiological adaptation to the extremes. In this communication water relation of six common lichens of Schirmacher Oasis growing in different water regime is presented. The elasticity modulus derived through psychrometric methods is utilized as marker of desiccation tolerance. It indicates the strechability of the cell wall and lesser the values of elasticity modulus higher would be the elasticity. The lichens growing in exposed and dry areas (Rhizoplaca melanophthalma, Umbilicaria decussata) had lesser elasticity modulus followed by ones growing in water drainage (Buellia frigida, U. aprina), while muscicolous (L. epibyron) and shade loving lichen (Xanthoria elegans) had higher values. Among all the lichens studied R. melanophthalma emerged as a better desiccation tolerant in Schirmacher Oasis by having comparatively lower osmotic potential at full turgor, lesser apoplastic fraction, elasticity modulus and water content at turgor loss point. The desiccation tolerance sequence of lichens studied are of following order; R. melanophthalma > U. decussata > U. aprina > B. frigida > X. elegans > L. epibryon. Further, the water holding capacity of U. aprina was maximum and ranged from 130.6 – 229.12 % of dry weight.

Keywords – PV curve, desiccation tolerance, stress physiology, adaptation.

*

E-mail: [email protected], [email protected], [email protected], Mobile: +919305227203 Lichenology Laboratory 2 Plant Physiology Laboratory, National Botanical Research Institute (NBRI-CSIR), Rana Pratap Marg, Lucknow – 226001, U.P., India 1

164

Sanjeeva Nayaka, Dalip K. Upreti and Ruchi Singh

INTRODUCTION Lichen is a composite plant consisting of symbiotically associated fungal (mycobiont) and algal or cyanobacterial (photobiont) partners. The mycobiont is usually an ascomycete and in very few cases a basidiomycete, and a photobiont is usually a green alga but in about 10% of lichens a cyanobacterium. Lichens are strictly dependent on ambient moisture for their metabolic activities. Unlike homiohydric vascular plants lichens lack stomata, cuticle and water transport system such as roots, xylem vessel and tracheids. Hence, they can not actively regulate their water content and are called as poikilohydrous organism. The homiohydric organisms are desiccation sensitive and die when water content falls below a certain threshold, where as poikilohydric organism include both desiccation-sensitive and desiccation-tolerant species. Desiccation-tolerance is the ability to revive from the air-dried state when water is provided. It is also found in prokaryotes, algae and bryophytes, and occasionally in pteridophytes, but very rare in the vegetative tissues of angiosperms or in animal tissues. The vast majority of lichens are desiccation-tolerant. Under natural conditions, the life of most lichens is exposed to rapidly changing water contents and correspondingly rapidly changing physiological activity such as respiration and photosynthesis (Kranner et al. 2008). Antarctica is a land of extremes. About 98% of the continent is permanently covered with ice, while remaining 2% of ice-free land is restricted mostly to the periphery of the continent. These ice-free areas are the only habitat available for the growth lichens. Antarctica is the coldest continent with heat balances is everywhere negative (Engelskjön 1986). It is the windiest of the continents with the highest wind speed measured at d'Urville (327 km/h). The wind can act in three ways, by desiccation, wind-chill and ice-blast. The absolute humidity in the continent is 0.03%, lower than that of the Sahara Desert. Low average humidity combined with the extreme cold make the South Pole region the world's driest desert. It rains very rarely in maritime Antarctica, otherwise the snowfall, which averages less than one inch annually is the major precipitation in the continent. The sun does not shine at the South Pole for six months of the year. When the sun does shine, much less solar energy actually reaches the ground at the Pole because the sun's rays pass through a thicker layer of atmosphere than at the Equator. Also, due to the predominance of ice and snow covering Antarctica, most of the sun's rays that do reach the ground are reflected back into space leaving the continent cold with un-molten ice mass. The freshwater lakes in Antarctica are mostly confined to certain ice-free areas as Larsemann Hills, Schirmacher Oasis, Bunger Hills and Vestfold Hills. These lakes, which remain frozen for most of the year, are fed by glacier and snowmelt streams during the short austral summer months. Despite the restricted availability of liquid water and other extremes a total of 439 lichens do exist in Antarctica (Øvstedal and Smith 2001; 2004), which can be directly attributed to their adaptation to the stressor (Kappen 2000). The adaptive stimulus is clearly expressed in lichens as they are the most successful elements of the terrestrial biota in Antarctica and have obvious dominance in ice-free areas. They are superior to bryophytes and perhaps also to free living algae and fungi, particularly in harsher regions (Kappen 2004). Lichens together with bryophytes or alone form the largest amount of standing biomass in Antarctic landscapes with up to 950 kgm-2 in continental and up to 1300 gm-2 in maritime Antarctic habitats (Kappen 2000). Nayaka et al. (2009) discussed in detail the adaptive response of Antarctic lichens to various stress in factors. The water being a major constrain in Antarctica physiological

Water Relation of Some Common Lichens Occurring in Schirmacher Oasis…

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adaptation to it is an interesting aspect for research. In the present study water relations of six common Antarctic lichens growing in different water regime in Schirmacher Oasis (SO) were studied in details. The aim of the study is to identify a lichen species that is physiologically better adapted to water stress in Antarctica. The aim is achieved by through psychrometric technique and measuring water holding capacity. This technique relies on water potential data from which pressure volume (PV) curve is constructed and various isotherms are derived. The PV isotherm is one of the widely used tools utilized for characterizing water status (Becket 1997). The PV isotherm has proved useful in assessing desiccation tolerance and the distribution of tree species in Malay-Thai peninsula (Baltzer et al. 2008). Many useful relations such as osmotic potential (OP) at full turgor, turgor loss point (TLP), relative water content (RWC) at TLP, elasticity modulus, solute concentration, symplastic, apoplastic and intercellular water contents can be measured with the help of PV curve.

MATERIALS AND METHODS Lichen Habitat and Species Selection Two important macro-habitats can be recognized in SO in relation to occurrence of lichens and source of water; 1). lake drainages, where water from one lake over flows to the another in summer, and 2). dry areas, where major source of water is snow melt. The lichens in SO are found growing on moraine, rock and moss in these habitats. Most of the lichens are directly exposed to sun while few are shade loving. A total of six lichens are selected for desiccation study and were identified by following Øvstedal and Smith (2001) (Table 1). The characteristics of the lichens are as follows; Buellia frigida Darb. – It is a crustose lichen, grey to blackish in colour, forms thick, circular patches on rocks. It is endemic to Antarctica, but one of the most common and wide spread lichens throughout the continent. In SO it is commonly occurs in lake drainages along with Umbilicaria aprina Nyl. and Rhizocarpon geographicum (L.) DC. It depends on lake drainage and snow melt for water. Lecanora epibryon (Ach.) Ach. – It is a crustose lichen with thick pale coloured thallus and prominent, circular apothecia found growing on moss. It is a bipolar species and also common in Antarctica. In SO it occurs in moist places near the lakes on the mosses. The snow melt and lake is its source of water. Rhizoplaca melanophthalma (Ram.) Leuckert and Poelt – It is a foliose lichen, yellow to yellow-green in colour, with prominent, crowded lecanorine apothecia, forms weakly lobate, smaller thallus on rock or moraine crusts. In very exposed habitats it appears grey-green to black. It is a cosmopolitan species and very common in Antarctica. In SO it occurs on rock and moraine crusts in exposed areas. Snow melt is its primary source of water. Umbilicaria aprina Nyl. – It is a foliose lichen, umblicate, usually monophyllous, 5 – 10 cm in size, dark grey to brown grey in colour. It is a cosmopolitan species and common in Antarctica. In SO it is the most prominent lichen, occurs mostly in lake drainage of lakes on rocks. Along with other species of Umbilicaria and Buellia it makes the lake drainage appear black in colour. The lake drain water is its major source of water. U. decussata (Vill.) Zahlbr. – It is a foliose lichen, umblicate, monophyllous, smaller in size, up to 3 cm in diam., button like, with wrinked upper surface and grows on rock. It is cosmopolitan in distribution, found in colder region and common in Antarctica. In SO it

Table 1. Antarctic lichen taxa analyzed for the water relation and their ecology

1 2 3 4 5 6

Sample

Habit

Habitat

Substratum

Buellia frigida Darb. Lecanora epibryon (Ach.) Ach. Rhizoplaca melanophthalma (Ram.) Leuckert & Poelt Umbilicaria aprina Nyl. U. decussata (Vill.) Zahlbr. Xanthoria elegans (Link) Th. Fr.

Crustose Crustose Foliose

Water drainage Dry area Dry area

Rock Moss Soil

Exposure to sun Exposed Partial shade Exposed

Foliose Foliose Foliose

Water drainage Dry area Dry area

Rock Rock Rock

Exposed Exposed Partial shade

Locality Priyadarshini Lake Near Circle lake North West of Maitri Priyadarshini Lake Vetehia nunatak Trishul Hill

Table 2. Water holding capacity and derivatives of PV curve for Antarctic lichens Sample 1 2 3 4 5 6

B. frigida L. epibryon R. melanophthalma U. aprina U. decussata X. elegans

Water holding capacity (% dry wt.) 70.9 – 110.57 90.62 – 145.24 120.83 – 187.2 130.6 – 229.12 115.51 – 220.62 148.42 – 208.22

OP at full Turgor (MPa) -1.02 ± 0.46 -0.90 ± 0.26 -0.90 ± 0.29 -0.64 ± 0.25 -1.63 ± 0.22 -0.85 ± 0.80

Apoplastic water fraction 12.0 ± 5.66 19.75 ± 7.50 12.29 ± 7.34 28.0 ± 8.3 21.38 ± 9.24 21.0 ± 5.31

Elasticity modulus (MPa) 6.42 ± 0.43 15.01 ± 5.12 3.98 ± 2.95 5.75 ± 3.03 4.55 ± 2.59 9.50 ± 4.50

Water content at TLP 61.75± 1.5 48.25 ± 5.91 67.43 ± 8.02 66.25 ± 3.4 58.75 ± 8.46 56.25 ± 2.2


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is found growing luxuriantly on rocks of Vitteheia and Baalsrudfjellet nunatak along with Pseudophebe minuscuala (Nyl. ex. Arnold) Brodo and D. Hawksw. Xanthoria elegans (Link) Th. Fr. – It is a foliose lichen, up to 5 cm in diam., orange in colour with radiating lobes. It is a cosmopolitan species very common in Antarctica. It is an attractive and very prominent due to its bright orange colouration. But in SO it is rare and found on rocks, in partially shaded, shelf facing side of Trishul Hill.

Water Holding Capacity About 10 –15 gm of fresh lichen samples were cleaned and kept immersed in water for 30 min to make it saturated. Then samples were blotted using paper towels to remove excess of water present over the thallus and the weight was taken. The samples were then kept in desiccator with silica crystals for 3 hrs and then transferred to hot air oven. The samples were dried for 70 hr at 50° C until the constant weight is attained. The water holding capacity is calculated as follows; Water holding capacity = [(Turgid weight – Dry weight)/Dry weight] x 100

Water Potential (Ψ) Measurement and Pressure Volume (PV) Curve About 15 – 20 mg of fresh samples of lichen were cleaned and kept in tap water for 15 30 min to make it fully turgid. Then samples were blotted using paper towels to remove excess of water present outside the thallus, quickly weighed and placed in chambers of Psypro Water Potential System. After equilibration for 4 hr chambers are connected to a Wescor HR-33T micro voltmeter and measured the water potential. Samples were then allowed to lose about 5–20% of their water and allowed to equilibrate again. Measurements were repeated until the water potential fell to below –5 MPa. Then the samples were dried for 70 hrs at 50° C in hot air oven and weight was taken. Psychrometer chambers were calibrated with standard solution 0.5 M of NaCl at 25° C. Values of Ψ are corrected to room temperature of 25° C. A total of 8 replicates were analyzed for each species. The water potential is represented as; Ψ = P – п, where P is turgor potential (TP) and п is osmotic potential. A PV curve was constructed by plotting 1/Ψ against relative water content (RWC) (Beckett 1995, 1997). The resulting curve is initially concave, but beyond the region where turgor is lost (i.e. where turgor no longer contributes to Ψ) the curve became linear. From the PV curve TP (P) was calculated at each Ψ as the difference between y-axis intercept value of the extrapolated linear portion of the curve and the actual Ψ (P = Ψ – п). The TP was then plotted as a function of RWC. The difference between total water content of the lichen thallus and the water content at which turgor starts falling is considered as inter cellular water. This intercellular water has to be deducted to actual water content within lichen. Hence, the RWCs for all the data were recalculated as follows; RWCc = [(Fresh weight – Dry weight) / (Turgid weight – Dry weight)] – Weight of intercellular water

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Figure 1. Representative PV curves of lichen species studied for water relations.

The PV curve reconstructed using RWCc and the OP (п) at full turgor is noted as the yintercept of the linear portion of the PV curve (Figure 1). Regression line going through this linear portion of the curve intercepts at x-axis and yields the symplastic and apoplastic fraction of water. Tissue elasticity was calculated from the relationship between Ψ and RWCc (Stadelmann 1984). The bulk elasticity modulus of tissue expresses the change in turgor of tissue cells for a unit change in the relative water content of the cells (e = dP/dr).

RESULTS The water holding capacity of Antarctic lichen varied from 70.9 – 229.12 % of dry of wt. (Table 2). The foliose lichen U. aprina, which has larger, thick thallus and grows on rock in lake drainages had maximum water holding capacity ranging from 130.6 – 229.12 % dry wt. However, a crustose lichen B. frigida, found in the same habitat but having smaller thallus has lower water holding potential which ranged from 70.9 – 110.57 % of dry wt. In general foliose lichens exhibited better water holding capacity in comparison to crustose.


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The Antarctic lichens exhibited varied level of desiccation tolerance as indicated by derivatives of PV curve in the present study (Table 2). The lichen growing in exposed areas, on moraine and rock are better desiccation tolerant, while muscicolous and shade loving ones are less tolerant. U. decussata had lowest OP (–1.63 ± 0.22 MPa) at full turgor and L. epibryon had lowest (48.25 ± 5.91) water content at turgor loss point. B. frigida had lowest apoplastic water while U. aprina had more (28.0 ± 8.3). The elasticity modulus of R. melanophthalma was lowest (3.98 ± 2.95 MPa) and it was maximum in muscicolous lichen L. epibryon (15.01 ± 5.12 MPa).

DISCUSSION The lichens, being exposed to frequent water stress have developed high degree of water holding capacity. They lack cuticle to impede entry of water in to the thallus. The spongy nature of the thallus tissue, presence of large intercellular spaces, the gelatinous sheath of algal cells and swollen hyphal wall allows them to hold good amount of water. The thalli often can absorb considerably more water during a prolonged immersion of several hours. The lichens are hygroscopic in nature and absorb moisture from the surroundings even at low humidity. The lichen can be hydrated and activated quickly by the snow, dew, mist or glacier meltwater and resume photosynthesis. Some lichens such as Umbilicaria having dark coloured thalii by absorbing sunlight become much warmer and can melt snow crystals deposited over them. Further, moistened thalli can reach an over-air temperature of nearly 23 K, which means that they can become as warm as 20˚C at maximum that induce maximal productivity. Some lichens are capable of gaining enough moisture from the humidity at the edge of a temporary snow patch on the rock without any visible melting process. Blum (1973) enumerated the water content (water holding capacity) of saturated thali of some lichens which ranged from 116 – 738 % of dry wt. (maximum in cyanolichen – Collema flaccidum (Ach.) Ach.). Umbilicaria pustulata (L.) Hoffm. held 201 % of dry wt. of water, in 5 min. of immersion, 203 % in 1 hr and 209 % in 15 hr. Similarly, Xanthoria parietina (L.) Beltr. held 178, 188 and 227 % of dry wt. of water in 5 min, 1 and 15 hr respectively. However, in case of Antarctic U. aprina, U. decussata and X. elegans their thallus reached full saturation within 30 min. of immersion with maximum of 229.12, 220.62 and 208 % of dry wt. of water respectively. This indicates the quicker response of Antarctic lichens when water is made available and an adaptation to combat water scarcity. The water holding capacity of crustose lichens in both the regions, i.e. main land (Blum 1973) as well as in Antarctica was lesser compared to foliose lichens. Unlike vascular plants, lichens can stay longer in desiccation state and their metabolic activity can recover after their tissues have been reduced to very low RWC. Such plants are called ‗‗resurrection plants‘‘ and have evolved desiccation tolerance (Alamillo and Bartels 2001, Bartels 2005; Tuba et al. 1998). The lichen can photosynthesize at low water potentials such as –20 MPa at –20˚C. Experiments in hot deserts have shown that lichens are able to photosynthesize even at low water potentials as low as –38 MPa (Nash et al. 1990). As soon as availability of moisture stops lichens thallus quickly desiccates, loses up to 97% of its water, and falls into an anabiotic state. Under low water potential photosynthesis rate will be low and can be considered as a means of keeping the photosynthetic apparatus intact and

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producing frost-protective carbohydrates than for actual dry matter. The psychrometric technique explores new possibilities to elucidating the water status of plants including cryptogams such as lichens, bryophytes, pteridophytes. According to several studies utilizing PV curve, an ideal desiccation tolerant lichen would have low OP at full turgor, lesser apoplastic water content, low RWC at turgor loss and more importantly less elasticity modulus. The low OP at full turgor indicates that the cell sap has low salt concentration and water potential would be high or near to zero. The lower apoplastic contents mean little quantity of water is present in the cell wall pores and more within in the cell (symplast), which contributes to high water potential. It is always necessary for a desiccation tolerant plant that it maintains turgidity of the cell even at lower amount of water. Hence, low RWC at turgor loss would be beneficial. Similarly, elasticity modulus indicates the stretchability of the cell wall. The low elasticity modulus value means high elasticity of cell wall and more tolerance for desiccation. Becket (1997) studied the PV isotherm of several poikilohydric plants including lichen Roccella hypomecha (Ach.) Bory., and also provided explanation for varied values of PV isotherms. The lichen R. hypomecha consisted low OP, low RWC at turgor loss, low elasticity modulus and low solute concentration. Proctor et al. (1998) studied the water contents of several bryophytes including a lichen Cladonia convoluta (Lam.) Cout., using PV relationship, where the lichen contained low OP, low RWC at TLC and low bulk elasticity modulus. In the present study all the lichens studied exhibited varied values for measured parameters. U. decussata had lowest OP (–1.63 ± 0.22 MPa) at full turgor, but slightly higher water content at TLP (58.75 ± 8.46) and apoplastic water (21.38 ± 9.24). B. frigida had lowest apoplastic water fraction (12.0 ± 5.66), but higher OP at full turgor (-1.02 ± 0.46 MPa). Similarly, L. epibryon had lowest water content at TLP (48.25 ± 5.91), but higher elasticity modulus (15.01 ± 5.12 MPa), apoplastic water content (19.75 ± 7.50) and OP at full turgor (-0.90 ± 0.26). Hence, it is has become necessary to relay on one strong parameter, compare other parameter accordingly and decide the desiccation tolerance of the lichens. The elasticity modulus is thought to be determined by the mechanical properties of cell walls (Cheung et al. 1975, Tyree and Hammel 1972). In leaf cells that have turgor elasticity modulus has a critical role in water relations. Advantage of the small elasticity modulus in the drought environment is that it contributes to the turgor maintenance of the leaf cells under conditions of low water content (Kozlowski et al. 1991). Hence, in the present study desiccation tolerances of lichens are compared based on their elasticity modulus. The lichens growing on moraine or rock in exposed areas are better desiccation tolerant and have lesser elasticity modulus. Among them R. melanophthalma exhibited lowest (3.98 ± 2.95) elasticity modulus indicating its highest desiccation tolerance. It is followed by U. decussata (4.55 ± 2.59), U. aprina (5.75 ± 3.03) and B. frigida (6.42 ± 0.43). It is obvious that lichens growing in exposed areas are the one who first experience the extremes of Antarctic conditions. They lose water either due to high irradiation, wind or low temperature and such conditions are very frequent in Antarctica. Hence, the cells of the lichens probably have become more stretchable or elastic. Where as in X. elegans, a lichen growing in partial shade at Trishul hill elasticity modulus is moderate (9.50 ± 4.50) indicating its medium level of desiccation tolerance. L. epibryon, a muscicolous lichen that grows in partial shade has highest elasticity modulus. The moss cushions acts like sponge and hold water for longer duration. Further, the mosses have many dead cells in their leaf tissue which again holds water. The moss in Antarctica usually grows in shaded area, between or under the rocks. The lichen by growing over them can obtain water for longer duration and hence developed less


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desiccation tolerance. In general, by considering all water relation parameters studied the foliose lichens R. melanophthalma can be considered as highly desiccation tolerant species. As discussed earlier it has low elasticity modulus, but also has comparatively lower low OP at full turgor (–0.90 ± 0.29 MPa), lower apoplastic water fraction (12.29 ± 7.34) and lower water content at TLP (67.43 ± 8.02). Further, water holding capacity of R. melanophthalma is considerably high which ranges from 120.83 – 187.2 % of dry wt.

CONCLUSION Among all the theories, the ‗adaptation‘ theory explains best the dominance of lichens in Antarctica. The lichens are adapted both morphologically as well as physiologically to the stress components of the continent. The water relation study carried out with the help of psychrometric method clearly indicates the differential levels of desiccation tolerance in Antarctic lichens. The habitat selection and restricted distribution of lichens is a clear strategy for the survival. Hence, X. elegans is found only on shelf facing side of Trishul hill in SO which receives shade at least for half a day during summer. The muscicolous lichen L. epibryon grows only on moss so that it gets water for longer duration. As per elasticity modulus desiccation tolerance is higher in sun exposed lichens, moderate in partially shaded and least in muscicolous. Hence, desiccation tolerance in Antarctic lichens is of following sequence; R. melanophthalma > U. decussata > U. aprina > B. frigida > X. elegans > L. epibryon. Further, water absorbance ability is faster and water holding capacity is higher which reaches up to 200% of their dry weight. Apparently, lichens did not develop ‗unique‘ adaptive mechanisms in the extreme Antarctic environment. The high desiccation tolerance and some morphological features of Antarctic lichens are also been observed in lichens growing in harsh climate of elsewhere (Kappen, 1988). However, the ability to tolerate stress, survive and evolve is high in Antarctic lichens.

ACKNOWLEDGMENTS We are thank full to the Director, National Botanical Research Institute for providing the necessary facilities, to Dr. U.V. Pathre for allowing us to utilize facilities of Plant Physiology Laboratory, to Council of Scientific and Industrial Research, New Delhi for financial assistance, to National Centre for Antarctic and Ocean Research, Vasco da Gama for selecting S.N. for 28th Indian Antarctic Expedition, to the leaders and members of the expedition for their cooperation during the collection of lichen samples, to Dr. Ajit Pratap Singh and members of Plant Physiology Laboratory for their cooperation during the study.

REFERENCES Alamillo, J. and D. Bartels: Effects of desiccation on photosynthesis pigments and the ELIPlike dsp 22 protein complexes in the resurrection plant Craterostigma plantagineum. Plant. Sci., 160, 1161-1170 (2001).

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Baltzer, J.L., S.J. Davies, S. Bunyavejchewin and N.S.M. Noor: The role of desiccation tolerance in determining tree species distributions along the Malay-Thai Peninsula. Funct. Ecol., 22, 221-231. (2008). Bartels, D.: Desiccation tolerance studied in the resurrection plant Craterostigma plantagineum. Integrative Comparative Biology., 45, 696-701 (2005). Beckett, R.P.: Pressure volume analysis of a range of poikilohydric plants implies the existence of negative turgor in vegetative cells. Annals of Bot. 79, 145-152 (1997). Beckett, R.P.: Some aspects of the water relations of lichens from habitats of contrasting water states studied using thermocouple psychrometry. Annals of Bot. 76, 211-217 (1995). Blum, O.B.: Water relations. In: The Lichens (Eds. V. Ahmadjian and M.E. Hale.). Academic Press, New York and London. pp. 381-400 (1973). Cheung, Y.N.S., T.M. Tyree and J. Dainty: Water relations parameters on single leaves obtained in a pressure bomb and some ecological interpretations. Can. J. of Bot. 42, 231235 (1975). Engelskjon, T.: Zonality of climate and plant distributions in some Arctic and Antarctic regions. Rapportserie Norsk Polarinstitutt, 30, 1-49 (1986). Kappen, L.: Ecophysiological relationships in different climatic regions. In: CRC Handbook of bchenology, Vol. II. (Ed. M. Galun.). CRC Press, Boca Raton, FL. 37-100 (1988). Kappen, L.: Some aspects of great success of lichens in Antarctica. Ant. Sci. 12(3), 314-324 (2000). Kappen, L.: The diversity of lichens in Antarctica, a review and comments. Biblioth. Lichenol., 88, 331-343 (2004). Kozlowski, T.T., P.J. Kramer and S.G. Pallardy: The physiological ecology of woody plants. Academic Press, New York, London (1991) Kranner, I., R.P. Beckett, A. Hochman and T.H. Nash III.: Desiccation tolerance in lichens: a review. Bryol. 111(4), 576-593 (2008). Nash III, T.H., A. Reiner, B. Demmig-Adams, E. Kilian, W.M. Kaiser and O.L. Lance: The effect of atmospheric desiccation and osmotic water stress on photosynthesis and dark respiration of lichens. New Phytol. 116, 269-276 (1990). Nayaka, S., D.K. Upreti and R. Bajpai: Diversity and adaptive response of lichens in Antarctica with special reference to Schirmacher Oasis. In: Frontiers in Fungal Ecology, Diversity and Metabolites (Ed. K.R. Sridhar.). I.K. Internataional Publishing House Pvt. Ltd., New Delhi. pp. 107-123 (2009). Øvstedal, D.O. and R.I.L. Smith: Addition and corrections to the lichens of Antarctica and South Georgia. Cryptogamie, Mycologie. 25(4), 323-331 (2004). Øvstedal, D.O. and R.I.L. Smith: Lichens of Antarctica and South Georgia. A guide to their identification and ecology. Cambridge University Press, U.K. (2001). Proctor, M.C.F., Z. Nagy, Z. Csintalan and Z. Takacs: Water-content components in bryophytes: analysis of pressure-volume relationships. J. of Exp. Bot. 49, 1845-1854 (1998). Stadelmann, E.J.: The derivation of the cell wall elasticity functions from the cell turgor potential. J. of Exp. Bot. 35, 859-868 (1984). Tuba, Z., M.C.F. Protor and Z. Csintalan: Ecophysiological responses of homoiochlorophyllous and poikilochlorophyllous desiccation tolerant plants: a comparison and an ecological perspective. Plant Growth Regulation. 24, 211-217 (1998). Tyree, M.T. and H.T. Hammel: The measurement of the turgor pressure and the water relations of plants by the pressure-bomb technique. J. of Exp. Bot. 23, 267-282 (1972).


Chapter 9

SOLAR WIND INFLUENCE ON ATMOSPHERIC PROCESSES IN WINTER ANTARCTICA O.A.Troshichev *, V.Ya.Vovk and L.V.Egorova ABSTRACT The paper presents a summary of the experimental results demonstrating the strong influence of the interplanetary electric field on atmospheric processes in the central Antarctica, where the large-scale system of vertical circulation is formed during the winter seasons. The influence is realized through acceleration of the air masses, descending into the lower atmosphere from the troposphere, and formation of cloudiness above the Antarctic Ridge, where the descending air masses enter the surface layer. The cloudiness formation results in the sudden warmings in the surface atmosphere, since the cloud layer efficiently backscatters the long wavelength radiation from the ice sheet, but does not affect the adiabatic warming process of the descending tropospheric air masses. The acceleration is followed by a sharp increase of the atmospheric pressure in the near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. As a result, the circumpolar vortex about the periphery of the Antarctic continent correspondingly decays and the cold air masses flow out to the Southern ocean. The latter phenomena evidently destroys the regular relationships between the sea level pressure fluctuations in the Southeast Pacific high and the North Australian-Indonesian low. It seems that the El-Niño beginnings are related exactly to the anomalous atmospheric processes in the winter Antarctica.

Keywords: Solar wind, Antarctica, atmosphere, anomalous winds, El-Niño.

* Eg225 mail: [email protected], Fax:+7-812-352-2688, Phone: 7-812-337-3134 Arctic and Antarctic Research Institute, St.Petersburg, 199397, Russia

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O.A.Troshichev, V.Ya.Vovk and L.V.Egorova

INTRODUCTION Existing models of the atmospheric variability and change do not take into consideration the short-term changes of solar activity. Indeed, the total energy, contributed by the solar wind and the cosmic rays in the Earth‘s atmosphere, is extremely insignificant in comparison with the total solar irradiance. But, as distinct from the total solar irradiance, the energy of solar wind and cosmic rays can increase in hundreds and more times in periods of high solar activity. The attempts to find the cause-effect relations between the solar activity variations and weather and climate changeability have a long story (Wilcox, 1975; Herman and Goldberg, 1978). The galactic cosmic rays (GCR) altered by solar wind were usually regarded as the most plausible agent of the solar activity influence on the Earth‘s atmosphere. The experimental data were presented showing the influence of the varying GCR flux on the Earth‘s weather and climate (Tinsley et al., 1989), on high cloud coverage (Pudovkin and Veretenenko, 1995), on temperature in the polar troposphere (Pudovkin et al., 1996, 1997), on the global total cloud cover (Svensmark and Friis-Christensen, 1997; Todd and Kniveton, 2001), on low cloud coverage (Marsh and Svensmark, 2003). These results suggest that just cloudiness variation affected by cosmic rays lead to changes in the atmospheric and meteorological characteristics. However, the hypothesis about the determining influence of the galactic cosmic rays on the cloudiness was not always supported by the subsequent, more detail research. It was indicated that the correlation with GCR disappears when the cloud coverage is decomposed in fractions by cloud type or height, by region (reduce for ocean basis), or by latitude (patterns in the tropical zone are better associated with concurrent El-Nino) (Farrar, 2000). A comprehensive study of the low cloud coverage for the last 120 years (Palle and Butler, 2002) revealed that the global cloudiness increased during the past century regardless of variations of GCR. The solar irradiance turned out to be correlated better and more consistently with low cloud cover than the cosmic ray flux (Kristjansson et al., 2002). As a result, the conclusion was maid that the mechanism linking the cosmic ray ionization and cloud properties cannot be excluded, but its high efficiency is not obvious (Harrison and Carslaw, 2003). At the same time it is well known that severe reductions in the galactic cosmic rays flux, known as Forbush decrease (FD), are related to the disturbed, high speed solar wind, emerging by the most intense solar flares. The disturbed solar wind is characterized by the largest changes in such parameters as the solar wind pressure PSW = m· n ·(VSW) 2 and the interplanetary electric field ESW = VSW x BZ (or simply the southward component of the interplanetary magnetic field (IMF BZS). The velocity VSW might vary with a factor of 2-3 at maximum, whereas the IMF BZ components might change the sign and increase by some factors of ten. The geoeffective solar wind parameters strongly affect (impact) the Earth‘s magnetosphere. It was noted that the FD beginnings at the Earth‘s orbit are recorded simultaneously with dramatic disturbances in the solar wind, and therefore, the atmospheric effects, assigned to Forbush decreases, can be, in reality, influenced by the geoeffective solar wind parameters (Troshichev et al., 2003). Figure 1. shows, as an example, response of the cloudiness above Vostok station (Antarctica) to Forbush decrease (left column) and to the IMF BZ minimum (right column) during the winter season of 1974-1992 (Troshichev et al., 2008). The list of 24 Forbush

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decreases was taken from the widely known analysis (Todd and Kniveton, 2001), but in our case the Forbush decrease maximum has been used as a key date in the epoch superposition method unlike to Todd and Kniveton (2001), who used the Forbush decrease beginning. Indeed, in many cases it is difficult to determine the FD beginning unambiguously, as a result the FD beginning dates sometimes are identified with as large a scatter as 5 days in various studies. On contrast, the Forbush event maximum is easily and uniquely identified by minimum in the galactic cosmic ray flux in each case. The same list has been used to separate the IMF BZ minimum dates, related to the FD events. Unfortunately, the IMF BZ data turned out to be available only for 15 events of 24. So, the left column in Figure 1. is for the data of cloudiness above Vostok, allocated relative to the FD maximum, whereas the right column is for the data allocated to the appropriate IMF BZ minimum.

Figure 1. Behavior of the average Forbush decrease (FD), the average interplanetary magnetic field (IMF) BZS component, and the appropriate cloudiness above Vostok for the most powerful FD events during the winter season of 1974-1992 (list of Todd and Kniveton, [2001]). A key date (t = 0) was taken as a day with FD maximum in the left column and a day with the IMF BZ minimum in the right column (from Troshichev et al.,2008).

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The results presented in the left column demonstrate that Forbush decrease coincides with increased cloudiness, which starts three days ahead of the key date (FD minimum) and reaches the 55 % maximum by the key date, the statistic significance being equal to 0.96. The results presented in the right column demonstrate, with no less evidence, that cloudiness above Vostok starts to increase one day before the IMF BZ minimum and reaches its maximum next day after the key date. The statistical significance in this case is less, ss=0.91, but we have to take into account that number of the available events was reduced in 1.5 times while examining the Bz indicator instead of Forbush decrease. This example clearly shows that changes of cloudiness may be successfully explained by Forbush decrease as well as by the IMF variations.

IMF VARIATIONS AS A DETERMINING FACTOR FOR THE CLOUDINESS ABOVE VOSTOK To demonstrate that variations in the interplanetary magnetic field by themselves can produce an effect on cloudiness we need to examine such solar wind disturbances, which were accompanied by the quite insignificant Forbush decreases. Taking into account that the Forbush decrease magnitude is negligible for the solar minimum epochs, the relation between the interplanetary magnetic field and the cloudiness above Vostok was examined for the years of the solar minimum (1974-1977 and 1985-1987) (Troshichev et al., 2008). The cloudiness at Vostok station was determined by two methods. The first method is based on estimation of cloudiness power in reports from the visual man-made observations (0 is for clear sky, 10 is for heavy cloudiness). The second method is based on measurement of the radiation balance (BR) value in MJ/m2 produced by balancer. It has been known that during the winter season, under conditions of the dark polar night, the radiation balance at Vostok is always negative. The larger negative BR values correspond to more intense radiation cooling, the less negative BR values indicate the cooling reduction as a consequence of the cloud layer formation above Vostok station. Figure 2. demonstrates the response of the radiation balance (second panel), the cloudiness balls (third panel) to the negative deviation in the daily averaged IMF Bz component (top panel) for three groups of BZ values: -2 < BZ < -1 nT (18 events), -2.5 < BZ < -2 nT (11 events), and BZ < -2.5 nT (13 events) in years of solar minimum (1974-1977, 19851987), the day of maximal negative BZ deviation being taken as a zero date (t = 0). One can see the evident response of cloudiness to influence of the interplanetary magnetic field: the greater the negative IMF BZ component, the larger is the cloudiness, the more pronounced is the reduction in the cooling. The cloudiness formation starts simultaneously with the negative BZ deviation (-1st day) and reaches the maximum at 0 or +1st day. It is important that statistical significance of all effects, being minor for the first BZ gradation, quickly grows with the increase of the negative BZ (in spite of the events number diminishing) and reaches 92% level in case of radiation balance for third BZ level. The crucial role of the interplanetary magnetic field was confirmed when examining the effects of the strong negative (ΔBZ2 nT) deviations of the IMF BZ component (Troshichev et al., 2008). As Figure 3. shows the intensification of the negative BZ deviation is followed, with a delay time of about 1 day, by the cloudiness enhancement

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and the corresponding warming in the ground layer, whereas the rise of the positive BZ deviation is followed by the opposite reaction: the cloudiness decays and the cooling starts on the ground layer. It should be reminded that Vostok is located at the ice dome at an altitude of 3.45 km above sea level, and, therefore, h=3.5 km corresponds to ground level at Vostok, whereas h= 6 km corresponds to an altitude of ~ 2.5 km above the ice sheet level. The results of the analysis (Troshichev et al., 2008), completed for conditions of the negligible Forbush decrease, demonstrate that the sign of the BZ component defines the trend of the cloudiness change (growth or decay), the cloudiness power being determined by the value of the southward IMF component. It seems reasonable to suggest that the formation of the cloud layer occurs at altitudes higher than ~ 5 km above the ice sheet.

Figure 2. Mean changes in cloudiness estimated from the radiation balance measurements (second panel) and by the visual man-made observations (third panel), obtained for three gradations of the negative deviation in the daily averaged IMF BZ component (-2 5, it is considered to severe case of geomagnetic storm; Kp < 4 is a geomagnetic quiet condition; and Kp = 4 is moderate case. The distribution aurora is not based on luminosity but on the measurement particle energy (Hardy et al., 1985). Handy studied the zones of electrons and ion flux in terms of Magnetic Local Time (MLT) at all level of geomagnetic activity quantified by Kp. Chubb and Hicks in 1970 used Kp to study the level and mechanism of aurora; according to them, the equator boundary of the oval expands about 1.7º equatorward per unit of Kp on the day side of the earth and 1.3º on the night-side while it moves by 1º-3º of latitude during Substorm time (Chubb and Hicks, 1970).

Satellite-Based Measurement Satellites with image capturing equipment (ultraviolet image sensing) are sent into the polar orbit to capture the snapshot of the atmosphere during their passes. Several projects of NASA‘s is based on studying auroral activity; the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetic, and Dynamic) mission is one of them. TIMED is aGlobal Ultraviolet Imager (GUVI) that provides cross-track scanned images of the Earth‘s ultraviolet airglow and auroral emission in the Far Ultraviolet (FUV) at wavelengths 115.0 to 180.0 nm, scanning imaging spectrograph that provides horizon-to-horizon images at five wavelength intervals (TIMED webpage http://www.timed.jhuapl.edu, 2008). It provides information of the ionosphere and thermosphere by monitoring all three regions: daytime mid-latitude, night-time low- to mid-latitude ionosphere and the high-latitude auroral zone, these regions are then characterized by energy and flux of the electrons (TIMED webpage http://www.timed.jhuapl.edu, 2008).

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EXPERIMENTAL SETUP AND METHODOLOGY The experiment was conducted on board of a Russian cargo ice class ship, the M. V. Emerald Sea, from Indian Bay (69.60º S, 12.43º E) on 27 February, 2007 to Larsemann Hills (69.06º S, 76.03º E) on 06 March, 2007. A NovAtel -602 GPS antenna installed on the deck of the ship as shown in Figure 3.(A) and is connected to GISTM based NovAtel 4004A GPS receiver installed in the radio room of the ship. The NovAtel -602 GPS antenna is choke ring designed used to minimize the multipath effect and the GPS receiver is operating on L1 C/A code and L2 carrier signal has 12 channels which can lock 12 satellites at a time. The GPS receiver has been logged with the following log command: GPGGA, GPGSV at 1 Hz rate, which we consider as positional file in ASCII format while the raw ionospheric file is binary file. The positional file provides position of the receiver in Real Time Kinematic (RTK) mode, satellite geometry, number of locked satellite along with their elevation angle, azimuth angle and their SNR (signal to noise ratio). The ionosphere file provides the TEC and ionospheric scintillation over phase and amplitude in binary format. The ship path followed during the experiment is shown in Figure 3.(B) and the figure represents that the ship remained in Antarctic circle throughout the experiment in order to observe aurora. The IPP (Ionospheric Pierce Point) at 300 km computed so as to identify the traces of GPS satellite in auroral oval. The position solution and IPP computed from receiver are transformed in MLT (Magnetic Local Time) frame of reference using coordinate transformation model (Alfven and Falthammar, 1963). The energy precipitation from the aurora was generated from TIMED satellites at the same time as the experiment; the direct polar plot of mean energy flux (E0) Vs MLT is archived from the TIMED web page.

Figure 3. A. Experimental set on the ship and GPS signal are shown passing through aurora. B. The red line indicate the ship path from Indian Bay (69.60º S, 12.43º E) to Larsemann Hill (69.06º S, 76.03º E).

REAL TIME KINEMATIC POSITIONING The real kinematic position is the process of estimating the position of any object in motion. Several parameters are used to estimate the position solution and error in any one

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parameter can degrade the position solution. In this study the position of the ship is estimated in real time using constant velocity and a constant acceleration model. In marine navigation, the precise position solution is very important. The GPS provides a position solution that does not degrade over time. However, the case may be different when there is an ionospheric storm. In real time kinematics, it is difficult to obtain a high precision position solution, because the stochastic properties of the system depend on factors, such as the ship‘s dynamic status and physical environment (e.g., rolling and pitching of ship on a rough sea), which are not always fixed. Therefore, efficient Kalman filtering algorithms have become an attractive research topic. In this study, the efficient Kalman modelling is not an issue because the Kalman filter algorithm has been used to estimate the position solution in real time. In this study, only the ionospheric condition related to aurora is correlated with the positional error obtained from the GPS receiver. The positional error of the ship in real time is computed in three steps. In the first step, the positional solution is computed by the software of receiver; in the second step, the position solution is estimated using constant velocity and constant acceleration model and filtering out the noises using Kalman filter. (The algorithm of the second stage is described in the next paragraph.) In the third stage, the position error is computed by taking the difference of the estimated positional solution from model with Kalman filter and position solution obtained from GPS in Cartesian coordinate frame. A constant velocity and acceleration model is used here to measure the update of positions, because it is assumed that the velocity of ship cannot be changed within a minute. A 9-dimensional state vector contains three components of position (x, y, z), three components of velocity (vx, vy, vz) and three components of acceleration (ax, ay, az). The average of velocity and acceleration for a minute is taken as a constant velocity and acceleration of the model for the next epoch, and each epoch is recorded at 1 sec. Figure 4. explains the real kinematic state of the ship; consider the ship is at point P at time t1 after one minute of initial stage the ship reached point Q. The velocity and acceleration obtained for 1 min are averaged to have one constant value which would be used to compute the position of the ship in next epoch therefore our first computation is at 1min 1 sec. When the ship reached to point R then the model will take the average value of velocity and acceleration obtained between points Q and R. The probable noises are filtered out through the Kalman filter model.

Kalman Filter The filter estimates the process state at some time and then obtains feedback in the form of (noisy) measurements. The mathematical process of Kalman filter falls into two groups: Time Update equations and Measurement Update equations. The time update equations are responsible for projecting forward solution by using the current state and error covariance estimates to obtain a priori estimates for the next time. The second is the measurement update equations, and it is responsible for the feedback (i.e. for incorporating a new measurement into a priori estimate to obtain an improved a posteriori estimate). Figure 5. shows the algorithm of the Kalman filter.

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Figure 4. Real Time Position for Ship.

Figure 5. Kalman filter algorithm.

The state model can be written as:

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x k 1  x k  tv x 

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(6)

Where qx, qy, qz are the process noise variance were assumed due to troposphere, multipath and stream of the sea (rolling and pitching).


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RESULTS AND DISCUSSION The mean energy spectrum of precipitating electron varies from eV to tens of keV, which is responsible for ionization in the E and F region of ionosphere. The lower mean energy ionizes the F layer; while, the E layer is ionized by the high level of mean energy (Kintner et al., 2002). The TEC value obtained from GPS depends upon these two layers therefore it is important to study the auroral effect on GPS to improve the accuracy of GPS based navigation during auroral storms. These regions are more interesting because they are accompanied by ionospheric irregularities that cause scintillations (Basu et al., 1985; 1993). The result of the research has been classified into two groups: one group represents a case study in which the ship was under the auroral oval region and the consequent effect on position solution; the second group describes when the ship was not under the influence of aurora. The horizontal error of both cases is taken into consideration so as to represent the effect of aurora on position solution. The position solution obtained here for both cases was taken for 24 hours to clarify the understanding of the effect of aurora. The whole day analysis of position error leads to a better understanding and produces consistency in our solution, because the auroral event lasts for 20 – 30 minutes of interval but it may range up to several hours during highly disturbed geomagnetic storms. The third group is statistical analysis of the result obtained during the ship vogue from source to final destination.

GPS POSITIONAL SOLUTION IN ACTIVE AURORA On 28th February 2007, TIMED spacecraft observed an aurora at three intervals when the ship was in the night time zone (according to MLT). The recorded time of auroral oval region by TIMED spacecraft is at 17:55, 19:32, and 21:09 UT (Figure 6) whose MLT times are 19:20, 20:37 and 22:28 respectively. The solid blue arrow with red boundary indicates the position of the ship within auroral activity as shown in the upper panel of the Figure 6. The IPP of locked PRNs are illustrated in the lower panel of Figure 6. The IPP illustrated in the lower panel of the Figure 6 indicates the signal of the locked PRNs actually passed through the auroral activity. Due to the presence of aurora activity, the number of satellite locked is 5 between 17:30 UT to 18:30 UT. Compared to the MLT and the IPP it was found that few of the PRN passed through the auroral oval. The SNR of the locked satellite are illustrated in Figure 7. and it indicates the most of the PRNs (4, 9, 12, 17, 20, and 28) signal passed through the aurora has very low SNR value. Out of 10 locked PRN, 5 were found to have SNR below 15dB, but the required SNR is 23 dB. (Senior and Honary, 2003) found that the fading of low frequencies is due to D layer of the ionosphere. However, the signal degrades at GPS L1 frequency due to diffraction of the signal from the precipitation of auroral energy (Titheridge, 1971). The fast moving auroral arcs are the evidence of particle precipitation that could cause ionospheric irregularities that affect the GPS signals in terms of fading of the GPS signal (Smith et al., 2008). Previous studies of the production and decay of plasma density from auroral precipitation in the F region calculate a production rate of 5–10 min and a decay rate of 10–20 min (Sojka

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and Schunk, 1986). The work in demonstrates the correlation of TEC derived from GPS with TIROS precipitating energy flux over 0.3–20 keV (Coker et al., 1995). They mentioned that short enhancement of TEC correlates with the precipitating electron flux. Aarons et al. (2000) have used Polar UVI data to study the production of fluctuations in GPS signal produced by TEC variations correlate well with increased TEC. Similar studies is seen in (Pi et al., 1997) where author considered worldwide GPS network to investigate GPS TEC fluctuations and present a case showing high-latitude TEC fluctuations in the evening and early morning during a magnetic storm. The TEC fluctuation can be produced by precipitating electron flux. The sum of this evidence is that TEC fluctuations occur in the same regions as active auroral displays. The tracking performance of GPS receiver can be degraded by the fluctuation of TEC and during periods of enhanced ionospheric activity in the high latitude auroral region is very significant (Skone, 2001). Figure 6 represents the case when the GUVI energy flux is approximately equal to 10 keV and when the GPS satellites are in the line of sight and the degradation in position solution is greater. The first panel of Figure 8 represents northing and easting error; the second and third panels represent the total number satellites locked and HDOP, respectively. Results show that when aurora activity is observed, a corresponding strong fluctuation in horizontal position is recorded. The evidence of enhanced TEC degrades the SNR of the signal and the degraded signal causes significant positional error. These variations are associated with smaller intensifications in the auroral oval, which are often observed as precursors to the more intense expansive phase velocity (Murphree et al., 1991). Due to high auroral activity the number of satellite locked also decreases and reaches the minimum number of 4 between 19:00 UT and 20:00 UT. With the decreases number of satellites, the geometry is affected and increased HDOP is also a source of positional error (Position Accuracy = HDOP x User Range Error). The easting error in Figure 8. shows one-to-one correlation with the PRNs affected by the auroral storm. Figure 8. also illustrates that the positional solution is smooth when there is no auroral storm.

GPS POSITIONAL SOLUTION IN QUIET AURORA Another event was selected when the auroral oval was not found in the line of sight of locked GPS satellites. The auroral oval was traced by TIMED satellite at 11:37 UT and 13:16 UT, illustrated in the upper panel of Figure 9. The corresponding MLT has been representing in polar plots with latitude circle. Based on the above mentioned time (UT), the position of ship was computed to find its position according to MLT at 11:37 UT. At two time periods, 11:37 UT and 13:16 UT, the ship was found around 14:00 MLT position within 65 degree of latitude circle.

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Figure 6. The upper panel represents the auroral precipitate energy and the lower represents the IPP of the GPS satellite passing through the aurora (computed in MLT reference).

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DOP ary of S2 244

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Rajesh Tiwari, Smita Tiwari, P. K. Purohit et al. Position Error 28 Feburary 2007

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An estimation of position of ship is purely based on MLT confined within the auroral plot, as indicated by the solid red arrow. The IPP of total number of visible satellite are illustrated in the lower panel of Figure 9. During this event the maximum number of locked satellites was 7. Figure 10. illustrates the effect of the SNR of the signal and the SNR value obtained indicate no degradation of the signal in the absence of aurora. The horizontal position errors are illustrated in the upper panel of Figure 11, the results show negligible horizontal position errors in terms of easting and northing. The second panel of the Figure 11. illustrates the number of locked satellites, and the third panel represents HDOP to study the satellite geometry. The results show that in the absence of auroral activity the position accuracy was fair and good. Though position error was recorded high around 06:00 UT to 15:00 UT due to the low number of satellites locked (4), the HDOP increased to 8. As mentioned in the previous section, the big value of HDOP is also responsible for positional error. Therefore, the positional error obtained is due to bad geometry.

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Figure 9. The upper panel represents the auroral precipitate energy and the lower represents the IPP of the GPS satellite not passing through the aurora (computed in MLT reference). PRN:6

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246 Horizontal Error (Meter)

Rajesh Tiwari, Smita Tiwari, P. K. Purohit et al. Position Error (Meter) 01 March 2007 20 East Error North Error

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STATISTICAL STUDY OF POSITIONAL ERROR To have a clear picture of positional error during auroral activity, we compute the statistics of absolute position error for complete ship journey. We divide the data into groups, according to auroral activity. In the first group, auroral activity is present and in the other, auroral activity is absent. For this purpose we compute mean, standard deviation and maximum value for the two groups (Table 1). From the table we found that on the days when auroral activity was present, the maximum horizontal and vertical error was more than 6 m and standard deviation was greater than 1; this is very high. In the absence of aurora, the position error is less than 4 m and standard deviation is less than 0.4. Due to the high auroral activity, the mean number of satellite locked is 5; as a result, the maximum HDOP is 7, which increases the probability of poor geometry. On the other hand, due to the absence of auroral activity in the Antarctic region, the mean number of satellites locked is greater than 9, which is sufficient for good geometry; therefore the maximum value of HDOP is 3.


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SUMMARY AND CONCLUSION We established strong correlations between GPS performance and auroral phenomena in the Antarctic region during the ship‘s movement. The precipitating energy flux over 0.3–20 keV correlated well with GPS-derived TEC (Coker et al., 1995). The auroral E region is the main source of TEC-induced phase fluctuations. The auroral activities are common at high latitudes. The performance of the GPS receiver degraded at high latitudes during auroral activities. Therefore, the higher the auroral energy, the higher the dynamic auroral arcs. TEC fluctuations produced by discrete auroral arcs will be more common and larger in the night side auroral ionosphere (Basu et al., 1993). The L1 ranging errors of at least 2 m will be introduced by auroral arcs into navigation systems for differential and augmentation (Kintner et al., 2002). In aurora region, degradation accuracy is of concern for communication and navigation. This issue is a concern for reliable operation of safety-critical GPS systems, such as marine DGPS (Differential Global Positioning System) services or SBAS (Satellite-Based Augmentation Systems) for aviation applications. During ionospheric disturbances over high latitude regions, users experience degraded position errors, and sometimes exceed tolerable limits. Our study shows that the precipitating energy flux over 7 keV energy degraded the position solution. Table 1. Statistics of Position Error during Auroral Activity Statistics Observations Horizontal Error (m) Vertical Error (m) HDOP No. of Satellite

Auroral Activity Present Mean Std Max 7.2 1. 5 8.9 7.5 1.4 6.4 5.4 1.7 7.0 4.9 1.1 11.0

Auroral Activity Absent Mean Std Max 2.5 0.5 3.3 2.6 0.4 3.1 1.6 0.2 3.0 9.1 0.1 11.0

ACKNOWLEDGMENTS The authors wish to acknowledge the financial support from NCAOR, Goa, Ministry of Earth Science, Govt. of India, under the Space Weather Programme at Antarctica. The authors also acknowledge the TIMED mission for providing aurora data.

REFERENCES Aarons, J., B. Lin, M. Mendillo, K. Liou and M. Codrescu: Global positioning system phase fluctuations and ultraviolet images from the Polar satellite. J. Geophys. Res., 105, 52015213 (2000). Alfven, H. and C.G. Fälthammar: Cosmical electrodynamics: fundamental principles. 2nd ed., Clarendon Press, 121-143 (1963).

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INDEX A abatement, 222 absorption spectroscopy, 120 access, 248 accessibility, 119 acclimatization, 131 acid, 62, 67, 97, 115, 229 active oxygen, 97, 99, 113 active site, 120 adaptability, 54 adaptation, 40, 68, 72, 74, 82, 95, 108, 139, 146, 163, 164, 169, 171 adaptations, viii, 68, 227 adenine, 119, 128 adjustment, 95, 111 advancement, viii adverse conditions, 11, 100, 107 adverse effects, 115 adverse weather, 44 aerosols, 18, 196 Africa, 2, 3, 135, 136 age, 24, 28, 40, 41, 222, 225 agriculture, 7 Air Force, 195 air pollutants, 70 air temperature, 5, 22, 67, 69, 74, 75, 79, 141, 169, 202, 213 Alaska, 224 Alaskan North Slope, 82 alcohols, 99, 103 alfalfa, 126 algae, 11, 41, 44, 47, 49, 50, 53, 56, 58, 59, 61, 62, 63, 66, 68, 72, 74, 75, 80, 82, 83, 84, 85, 87, 95, 98, 99, 104, 109, 129, 131, 133, 164, 228, 230 algorithm, 238, 239 alien species, 41 alpha-tocopherol, 95 alters, 16, 104, 126, 146

amino, 94, 99, 114, 228, 229 amino acid, 94, 99, 114, 228, 229 amino acids, 94, 99, 114, 229 ammonia, 66, 115, 141 amplitude, 85, 180, 208, 235, 237 anatomy, 96 ancestors, 57 antioxidant, 95, 97, 100, 104 antithesis, 126 appropriate technology, 223 aquatic habitats, 138 Arabidopsis thaliana, 104, 125 Argentina, 105, 127, 146, 147 arthropods, 50 Asia, 2 assessment, 34, 51, 52, 53, 58, 82, 84 assimilation, 66 atmosphere, 1, 4, 5, 6, 8, 9, 10, 14, 15, 16, 17, 18, 20, 22, 24, 27, 30, 31, 33, 34, 43, 67, 70, 72, 75, 84, 86, 89, 91, 164, 173, 174, 178, 180, 183, 184, 186, 193, 194, 195, 196, 199, 200, 208, 209, 215, 216, 217, 218, 224, 225, 227, 228, 233, 234, 236 atmospheric pressure, 9, 43, 173, 184, 185, 187, 194 autecology, 124 authorities, xv automobiles, 228 avoidance, 68, 111

B bacteria, 47, 58, 68, 70, 83, 107, 118, 132, 226 bacterium, 58, 68, 70, 83 banks, 53, 54, 61, 143 barriers, 15 base, 14, 57, 97, 118, 119, 126, 203 base pair, 126 behavioral change, 223 behavioral intentions, 223 bending, 116

250

Index

benthic diatoms, 101 Big Bang, 230 biochemistry, 101, 123 biodiesel, 230 biodiversity, 47, 90, 109, 133, 223, 227, 228 biogeography, 150 biological activity, 231 biological samples, 44, 45, 63, 64 biological systems, 72 biomass, 32, 34, 39, 50, 59, 62, 66, 73, 81, 84, 112, 129, 145, 164 biosphere, 67 biosynthesis, 145 biosynthetic pathways, 115 biotic, 47, 48, 49, 63, 81 birds, 39, 40, 44, 48, 50, 53, 56, 57, 58, 70, 80, 81, 226 bleaching, 224 body fluid, 55, 79 bonding, 75, 79 branching, 112 Brazil, 135 breeding, 222 Britain, 90 bryophyte, 97, 98, 108, 112, 114, 125, 128, 133, 140, 145 burn, 133, 221, 222, 226, 228 buttons, 109

C cabbage, 143 cadmium, 123 calcium, 66 campaigns, 201 carbohydrate, 96, 97 carbohydrates, 59, 101, 121, 142, 143, 145, 148, 170 carbon, 6, 9, 10, 15, 32, 34, 39, 63, 66, 67, 77, 81, 97, 105, 108, 126, 128, 143, 146, 147, 221, 222, 224, 225, 226, 228 carbon dioxide, 6, 9, 15, 34, 105, 126, 128, 146, 147, 221, 222, 224, 226 carbon monoxide, 6 carefulness, 9 carotene, 94, 95, 98 carotenoids, 72, 82, 98, 100, 102, 131 case study, 241 cation, 120 cellulose, 100, 103, 222, 228 chaos, 221, 223, 228 chemical, 5, 9, 10, 11, 63, 222 chemical characteristics, 11 chemical properties, 222 chemical reactions, 9

chemicals, 15, 55, 97 China, 86 chlorine, 7 chlorophyll, 51, 66, 73, 95, 98, 100, 101, 102, 112 chloroplast, 100 chromosome, 118 circulation, 14, 33, 34, 36, 85, 173, 178, 179, 194, 195, 219, 222, 225 cities, 225 civilization, 230 clarity, 22 classes, 59, 60, 61, 68, 116, 205 classification, 57 clean energy, 230 cleaning, 17 cleavage, 121 climate, vii, viii, 1, 2, 5, 7, 8, 9, 10, 12, 15, 18, 36, 37, 39, 41, 42, 48, 56, 67, 74, 77, 79, 84, 86, 91, 96, 98, 108, 121, 123, 128, 139, 143, 157, 171, 172, 174, 195, 196, 199, 200, 201, 202, 218, 223, 224, 225, 226, 227, 231 climate change, 1, 5, 12, 18, 36, 121, 128, 139, 143, 174, 223, 224, 225, 227 climates, 75, 77 climatic factors, 8, 67, 68 CO2, 9, 31, 32, 85, 124, 128, 221, 222, 227, 228, 231 coal, 3, 221, 222, 228 coastal region, 7, 9, 10, 40, 84, 109 colonization, 40, 84, 105 combined effect, 110, 127, 181 commercial, 3, 4, 7 communication, 163, 247 communities, 40, 50, 51, 52, 53, 77, 80, 82, 86, 97, 98, 108, 111, 131, 143, 144, 145 community, viii, 12, 34, 59, 60, 61, 84, 104, 146 compatibility, 87 competition, 223 complexity, 48, 113 composition, 5, 63, 75, 79, 101, 104, 105, 110, 125, 127, 128, 143, 146, 147 compounds, 9, 18, 97, 99, 100, 101, 104, 113, 115, 116, 121, 122, 127, 140, 142, 143 computation, 238 condensation, 77, 208 conduction, 74, 75 conductivity, 63, 193 conductor, 14 conference, 90 configuration, 216 conservation, ix, 12, 57, 87 consolidation, 158 constant rate, 5 constituents, vii

251

Index construction, 10 consumers, 11, 49, 50, 51, 54, 56, 59, 101 consumption, 68, 85, 230 consumption rates, 68, 85 contamination, 32 Continental, 32, 108, 109, 133, 142, 144, 196 contour, 209 convention, 211 convergence, 2 cooling, 15, 16, 20, 43, 55, 56, 68, 79, 176, 177, 178, 180, 183, 194, 199, 208, 221, 225, 228 cooperation, 171 coordination, 31 copper, 4 correlation, 87, 174, 180, 189, 211, 242 correlations, 247 cortex, 97, 115, 123 cosmic ray flux, 174, 175, 196 cosmic rays, 174, 195, 196 cost, 112, 223 courtship, 57 covering, 3, 44, 164 critical analysis, 11 criticism, xv crop, 62, 72, 87, 226 crop production, 226 crops, 10, 105, 128, 226 crust, 3, 158 crystal structure, 126 crystalline, 41 crystals, 70, 167, 169, 219 Cuba, 144 culture, 230 curricula, 223 cuticle, 55, 164, 169 cycles, 40, 108, 112, 125, 142, 145, 207, 209, 213, 224 cycling, 33, 48, 58, 59, 132 cyclones, vii, 15, 16, 17, 18, 31, 39, 40, 42, 43, 46, 67, 69, 70, 79, 85 cytoplasm, 116 cytosine, 126

D danger, 228 data set, 69 decay, 177, 189, 241, 248 decomposition, 39, 59, 67, 81, 82, 84 defence, 107, 111 deficit, 104, 200 deforestation, 224 degradation, 75, 102, 112, 234, 242, 244, 247 dehydration, 95, 143

deposition, 16 deposits, 3, 10, 123, 225 depression, 47, 141 depth, 6, 7, 26, 28, 35, 40, 42, 47, 66, 67, 73, 110, 139, 202, 203, 215 derivatives, 96, 166, 169 desiccation, 41, 55, 71, 87, 97, 99, 113, 115, 116, 127, 128, 140, 141, 142, 163, 164, 165, 169, 171, 172 destruction, 99, 100, 105 developed nations, 221, 222, 228 developing countries, 222 developing nations, 221, 228 deviation, 176, 177, 180, 183, 186, 192, 246 dew, 41, 70, 75, 77, 80, 169 DHS, 126 diffraction, 241, 248 diffusion, 28 disaster, 221 diseases, 226 displacement, 222 dissociation, 121 dissolved oxygen, 47 distribution, 10, 21, 35, 51, 55, 67, 68, 70, 84, 89, 95, 97, 99, 105, 110, 118, 121, 124, 125, 127, 132, 133, 138, 145, 149, 150, 156, 158, 159, 161, 165, 171, 187, 189, 236 diversity, 8, 39, 40, 47, 77, 80, 82, 96, 108, 147, 150, 172 DNA, 72, 107, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129 DNA damage, 115, 116, 117, 118, 121, 122, 126, 129 DNA lesions, 117, 118, 119, 122, 128 DNA repair, 118, 121, 125 DOI, 34, 35, 36 dominance, 62, 164, 171 drainage, 163, 165, 166, 178, 181, 187, 195 dream, 107 drinking water, 4, 222 drought, 37, 75, 77, 95, 97, 115, 141, 170, 226 dry matter, 170 drying, 47, 55, 98, 116, 128, 142 DS-1, 83 duality, 112

E ecology, 41, 74, 79, 84, 126, 133, 144, 145, 147, 161, 166, 172 ecosystem, viii, 5, 34, 39, 44, 47, 48, 54, 58, 59, 62, 63, 67, 69, 70, 72, 73, 74, 75, 79, 81, 83, 84, 85, 122, 123, 143, 146, 226 editors, iv, xv

252

Index

effluent, 231 egg, 57 elasticity modulus, 163, 165, 168, 169, 170, 171 electric current, 192, 193 electric field, 173, 174, 180, 181, 184, 193, 194, 195 electricity, 196 electron, 10, 99, 119, 120, 123, 235, 241, 242, 248 electrons, 236 elongation, 100, 105 emission, 221, 222, 228, 236 enemies, 57 energy, 5, 8, 9, 14, 15, 16, 17, 18, 29, 39, 41, 45, 47, 48, 49, 58, 59, 66, 67, 69, 71, 72, 75, 78, 79, 80, 91, 96, 97, 98, 118, 120, 121, 132, 164, 174, 199, 200, 211, 212, 219, 221, 222, 223, 228, 229, 230, 233, 234, 235, 236, 237, 241, 242, 243, 245, 247 energy consumption, 230 energy transfer, 230 engineering, 222, 223, 226 entropy, 221, 223, 224, 226, 228, 231 environment, iv, vii, viii, ix, 1, 3, 4, 5, 7, 8, 10, 11, 13, 15, 17, 20, 22, 23, 32, 40, 41, 43, 45, 47, 48, 49, 50, 61, 67, 68, 70, 75, 77, 79, 81, 84, 85, 98, 116, 124, 126, 127, 132, 133, 146, 150, 170, 171, 223, 224, 226 environmental aspects, 224 environmental change, viii, 123, 144 environmental conditions, viii, ix, 5, 11, 91, 95, 96, 97, 99, 132, 133, 138, 139 environmental control, 143 environmental factors, 47, 96, 99, 223 environmental influences, 41 Environmental Protection Agency (EPA), 227 environmental stress, 113 environmental stresses, 113 environmentalism, 231 enzyme, 39, 115, 118, 119, 120, 127, 141 enzymes, 100, 103, 104, 115, 118, 119, 121, 140 epidermis, 114 EPR, 120 equilibrium, vii, 16 equipment, 10, 236 ERA, 35 erosion, 30 eukaryotic, 119 Europe, 2, 159 evaporation, 15, 42, 67, 71, 72, 98, 108, 150, 225 evidence, 5, 77, 98, 100, 112, 113, 176, 196, 241, 242 evolution, 32, 48, 68, 81, 85, 86, 104, 118, 122, 127, 139, 143, 223 excision, 128

excitation, 119, 120 exclusion, 100, 103 exploitation, 223 exposure, 40, 46, 55, 97, 98, 99, 100, 104, 112, 115, 123, 128, 140, 142, 180, 224 external influences, 40, 85 extinction, 103, 125, 222, 225, 226, 228 extreme cold, 10, 95, 131, 164

F FAD, 119, 120 families, xv, 55 fat, 57 fatty acids, 142 fauna, 39, 48, 50, 51, 63, 66, 80, 84, 85, 86, 87, 131 fertility, 66 fertilization, 75, 77, 80 fertilizers, 10 films, 223 filters, 101, 122, 124 filtration, 49 financial, 81, 171, 247 financial support, 247 fish, 57 fixation, 143 flavonoids, 96, 99, 100, 103, 113, 122, 124, 125, 128, 145, 147 flexibility, 104 flight, 58, 70 flights, 70 floods, 226 flora, viii, 3, 4, 11, 39, 40, 41, 44, 47, 48, 49, 50, 51, 56, 67, 68, 70, 71, 72, 75, 77, 79, 80, 81, 86, 87, 90, 91, 95, 96, 100, 102, 104, 105, 108, 121, 128, 131, 132, 133, 139, 143, 146, 149, 153, 157, 159, 160, 161, 227, 228 flora and fauna, 3, 4, 11, 39, 40, 41, 44, 47, 67, 68, 70, 71, 72, 79, 81, 90, 100, 227, 228 flowers, 11 fluctuations, 112, 141, 173, 189, 195, 215, 242, 247 fluorescence, 98, 112, 124 food, 11, 40, 47, 48, 50, 51, 54, 58, 59, 75, 80, 81, 101, 223, 225, 228 food chain, 11, 48, 58, 59, 80 food web, 58, 101 force, 15, 186, 187, 200 formation, vii, 7, 10, 13, 14, 15, 16, 17, 18, 22, 24, 28, 35, 39, 41, 66, 67, 68, 69, 70, 75, 77, 79, 99, 116, 117, 120, 121, 125, 126, 132, 173, 176, 177, 180, 187, 189, 194, 200, 218, 222 formula, 186 fossils, 4 fragments, 52, 53, 54, 139

253

Index freedom, 12 freezing, 9, 16, 18, 44, 50, 55, 56, 62, 68, 95, 98, 99, 103, 113, 125, 133, 140, 141, 142, 145, 150, 193, 222 frequency distribution, 205, 206 freshwater, 28, 47, 56, 63, 68, 86, 107, 164 frost, 74, 150, 170 fruits, 11 fuel consumption, 222 functional analysis, 104, 127 fungi, 47, 56, 58, 70, 73, 86, 95, 99, 118, 131, 132, 164 fungus, 121 fusion, 75, 79, 230

G gametophyte, 142 gene expression, 127 genes, 124, 144, 145 genetic code, 117 genetic diversity, 133 genetic information, 118 genome, 118, 119 genus, 54, 55, 57, 58, 96, 132, 146, 149, 158, 159, 160 geography, 5, 86 geometry, 110, 237, 242, 244, 246 Georgia, 87, 126, 132, 134, 136, 149, 150, 157, 159, 160, 161, 172 Germany, 90, 125, 161 germination, 71, 112 global climate change, 121 global scale, 82 global warming, 5, 7, 17, 22, 27, 33, 35, 36, 82, 219, 221, 222, 223, 224, 225, 226, 227, 228, 231 glucose, 228 glycerin, 99 glycerol, 55 google, 224 GPS, 233, 234, 235, 236, 237, 238, 241, 242, 243, 245, 247, 248 gracilis, 51, 155 graph, 205, 209 grass, 11, 99, 103, 125, 132, 143, 144 grasses, 133 gravitation, 8 gravity, 15, 16, 202 grazing, 101, 104 green alga, 61, 62, 72, 73, 80, 86, 96, 97, 99, 164 greenhouse, 28, 34, 74, 223, 224, 225, 227 greenhouse gases, 223, 224, 225 growth, 11, 14, 36, 39, 40, 44, 47, 49, 50, 51, 55, 61, 62, 63, 66, 67, 68, 73, 79, 80, 81, 83, 87, 91, 95,

97, 98, 100, 102, 104, 105, 106, 107, 108, 111, 112, 115, 121, 127, 128, 129, 140, 141, 142, 143, 146, 147, 148, 164, 177, 225 growth rate, 36 growth temperature, 98 Guangzhou, 86

H habitat, 41, 44, 47, 50, 54, 55, 57, 61, 68, 70, 75, 78, 79, 85, 96, 97, 107, 115, 132, 138, 164, 168, 171, 225, 226 habitats, 41, 49, 51, 52, 53, 67, 95, 123, 125, 127, 131, 132, 139, 141, 142, 149, 164, 165, 172, 222 hair, 99, 144 hardness, 42, 66 harmful effects, 101, 113, 222 harvesting, 119 hazards, 9, 226, 228 health, 104, 143, 223, 226 heat loss, 200 heat transfer, 17, 78, 219 height, 6, 10, 13, 22, 23, 24, 34, 57, 67, 157, 174, 184, 185, 186, 215, 218 hemisphere, 8, 42, 57, 110, 113, 157, 160, 189, 195, 196, 197 heterogeneity, 61, 75, 79 high winds, 14, 27 histogram, 206, 207 histones, 119 history, iv, 1, 5, 11, 31, 86, 103, 127, 147, 201, 222 Holocene, 40, 86 hot springs, 99 House, 10, 12, 160, 172 human, 1, 4, 5, 9, 11, 40, 45, 57, 63, 66, 70, 82, 224, 226, 230 human activity, 1, 5, 66, 82 humidity, 9, 39, 42, 43, 47, 51, 67, 71, 79, 141, 142, 164, 169 humus, 63, 81, 95 Hungary, 127 hunting, 222 hurricanes, 225 hyaline, 136 hybrid, 223 hydrocarbons, 3 hydrogen, 99, 125 hydrogen peroxide, 99 hydroxyl, 99, 113 hydroxyl groups, 113 hypothesis, 174, 213

254

Index

I ideal, 5, 40, 72, 73, 96, 170, 201 identification, 51, 52, 53, 87, 96, 126, 133, 161, 172 identity, 5 image, 236 images, 236, 247 imagination, 11 IMF, 174, 175, 176, 177, 178, 180, 187, 188, 189, 191, 194, 197, 234 immersion, 169 immigration, 40 Impact Assessment, 224 impulses, 193 in vitro, 125 incidence, 107, 108 income, 194 India, ix, xi, xii, xiii, xv, 1, 3, 9, 13, 18, 31, 34, 35, 39, 81, 85, 89, 90, 91, 105, 107, 131, 149, 153, 154, 155, 156, 158, 160, 163, 221, 230, 231, 233, 247 individuals, 65, 121 induction, 126, 128 industrialization, 10 industries, 226 industry, 7, 224 ingredients, 227 inhibition, 72, 84, 122 insects, 47, 54, 55, 68 institutions, xv insulation, 75, 80, 204 integrity, 97, 100 interface, 15 interference, 1 intervention, 9 intrusions, 41 inversion, 13, 16, 20, 21, 24, 25, 29, 30, 200, 201, 213, 215, 217, 218, 219 invertebrates, 40, 50, 51, 68, 74, 75, 80, 118 ionization, 4, 174, 193, 241 iron, 3, 99, 149 irradiation, 103, 104, 105, 128, 147, 170, 193 islands, 2, 3, 39, 40, 108, 109 isolation, 41, 132, 149, 157, 160 isomers, 116, 118, 125 isotherms, 165, 170 isotope, 33 issues, iv, ix, 7, 12, 87, 231 Italy, xi, xii, 34, 86, 199

J Jamaica, 87

Japan, 86 Jordan, 32

K kaempferol, 113, 114

L laboratory studies, 72 lactic acid, 58, 83 lakes, 10, 16, 39, 42, 44, 47, 49, 51, 53, 54, 56, 61, 63, 66, 78, 81, 85, 91, 98, 99, 108, 138, 139, 141, 144, 145, 164, 165, 231 landscape, 72 landscapes, 145, 146, 164 Late Pleistocene, 86 laws, 230 leaching, 145 lead, vii, 16, 17, 20, 22, 23, 24, 74, 78, 116, 132, 174, 187, 195, 225, 226 legs, 55 Lepidoptera, 85 lesions, 116, 118 lice, 56 lichen, viii, 11, 47, 49, 50, 51, 52, 53, 61, 68, 71, 74, 75, 77, 80, 82, 85, 95, 96, 101, 102, 103, 108, 115, 122, 124, 125, 131, 145, 149, 150, 153, 157, 158, 160, 163, 165, 166, 167, 168, 169, 171 life cycle, 11, 67, 68 light, 11, 27, 31, 47, 49, 50, 51, 57, 62, 66, 67, 68, 73, 74, 75, 77, 97, 98, 99, 100, 102, 106, 116, 118, 119, 120, 122, 123, 124, 142, 144, 228 lipids, 99, 100, 142 living conditions, 50 logistics, 81, 217 Louisiana, 225 low temperatures, 4, 68, 74, 83, 85, 141 luminosity, 236 lutein, 95 lying, 99, 132 lysis, 62

M macroalgae, 102 macromolecules, 97 magnesium, 66 magnetic field, 5, 174, 175, 176, 180, 181, 195, 233, 234, 236 magnetism, 4 magnetosphere, 174, 187, 192, 193, 194, 233, 234, 236 magnitude, 176, 201

255

Index majority, 47, 58, 99, 132, 164 mammal, 87 mammals, 48 man, 149, 176, 177 management, ix manganese, 4 manipulation, 142 marine environment, 18 mass, vii, 14, 15, 16, 28, 34, 36, 37, 164, 178, 179, 181, 200 materials, 41, 56, 58, 66, 80, 147 matrix, 240 matter, iv, 14, 17, 22, 67, 73, 226 measurement, 5, 10, 44, 96, 143, 172, 176, 200, 202, 203, 204, 236, 238 measurements, 6, 24, 35, 36, 41, 43, 44, 72, 82, 86, 96, 127, 128, 177, 180, 185, 200, 202, 203, 238, 248 mechanical properties, 170 medulla, 115 melanin, 95, 97 melt, 4, 10, 28, 36, 45, 47, 50, 52, 97, 98, 99, 108, 116, 141, 165, 169, 201, 221, 222, 223, 225, 226, 230 melting, 7, 16, 28, 31, 36, 42, 44, 47, 74, 132, 169, 211, 221, 222, 224, 226 melts, 7, 8, 10, 14, 16, 222 membranes, 101 meta analysis, 113, 140 meta-analysis, 123, 127 metabolism, 101, 103, 104, 113, 124, 140, 143, 144 metabolites, 102, 103, 124 metals, 105 meter, 10, 62, 225, 227 microbial communities, 147 microbiota, 77, 80 microclimate, 49, 67, 125, 142 microcosms, 126, 146 microenvironments, 61 micrograms, 56 microhabitats, 81 microorganism, 34, 84 microorganisms, 11, 15, 22, 39, 47, 58, 66, 71, 75, 78, 79, 80, 83, 102, 108, 126 microscope, 50 migration, 40, 226 mineralization, 67 mission, 236, 247 mixing, 16, 22, 27, 29, 70, 85, 208, 215 MLT, 236, 237, 241, 242, 243, 244, 245 model system, 72 modelling, 32, 35, 218, 238 models, 10, 23, 34, 36, 68, 174, 199, 200, 201

modulus, 163, 166, 170 moisture, 11, 15, 17, 49, 67, 70, 71, 77, 80, 109, 112, 142, 164, 169 moisture content, 71, 112 molecular biology, 124, 144 molecular weight, 118 molecules, 97, 104, 107, 111, 113, 114, 118, 227 momentum, 14, 36, 45, 202 monoclonal antibody, 125 Montana, 224 Morocco, 83 morphology, 96, 98, 115, 140, 142, 248 motivation, 223 mutagenesis, 120, 133, 147 mutant, 127 mutation, 117 mutations, 117, 118

N NaCl, 167 natural disaster, 225 natural disasters, 225 natural gas, 3 natural resources, 223 navigation system, 247 negative effects, 98, 115, 121, 140 nematode, 84 Netherlands, 123, 144, 146 neutral, 233 New Zealand, 3, 90, 102, 110, 125, 144 nitrogen, 33, 61, 66, 68, 95 nitrogen fixation, 61, 68 nitrous oxide, 224, 226 Nitzschia, 92, 94 non-enzymatic antioxidants, 100 North America, 2 Norway, 82 NPL, 31, 33, 43, 81 nucleation, 36, 147 nuclei, 208 nucleic acid, 91, 100 nucleus, 118 nutrient, 40, 47, 48, 50, 59, 66, 73, 81, 91, 132 nutrients, 46, 47, 48, 50, 63, 66, 104, 112, 128 nutrition, 47

O obstacles, 3, 74 oceans, vii, 3, 5, 10, 15, 107, 225 oil, 3, 4 operations, 217 opportunities, vii, 139

256

Index

orbit, 174, 224, 230, 236 ores, 3, 11 organic compounds, 48 organic matter, 40, 46, 48, 51, 66 organism, 48, 66, 70, 81, 95, 96, 100, 113, 164 organs, 141 oscillation, 33, 191, 193, 196, 197 osmosis, 69 oxidation, 32, 66, 73, 81, 100 oxidative damage, 100, 104, 114 oxidative stress, 100, 103, 106 oxygen, 9, 15, 46, 49, 67, 70, 99, 100, 104 oxygen consumption, 67 oxygen consumption rate, 67 ozone, vii, 5, 6, 7, 9, 10, 11, 72, 84, 89, 91, 95, 98, 99, 102, 103, 104, 107, 110, 111, 112, 113, 116, 121, 123, 124, 125, 126, 127, 128, 129, 131, 140, 223

P P. sulcata, 155 Pacific, 2, 5, 173, 187, 189, 195, 197, 218 Paraguay, 135 parallel, 234 parasites, 56 parthenogenesis, 55, 56 pasture, 83 peat, 40 percentile, 227 periodicity, 208 permeability, 100 peroxidation, 100 petroleum, 222 phenolic compounds, 103, 113 phenylalanine, 115, 141 phosphate, 66 phospholipids, 97 phosphorus, 95 photosynthesis, 11, 50, 59, 63, 66, 68, 71, 72, 73, 75, 77, 83, 84, 85, 86, 96, 98, 100, 101, 102, 104, 105, 107, 111, 112, 121, 127, 129, 141, 142, 143, 144, 146, 164, 169, 171, 172 photosynthesize, 75, 77, 169 phycocyanin, 95, 99 phycoerythrin, 99 physical environment, 238 physical properties, 1, 4, 68 physical structure, 17 physicochemical characteristics, 63 physics, 231 Physiological, 106, 122 physiology, 87, 99, 101, 146, 163 phytoplankton, 72, 84, 101, 105

pigmentation, 97, 102, 103, 104, 115, 126, 131 pioneer species, 73 plankton, 101, 227 plant growth, 62, 73, 127 plants, 10, 11, 39, 40, 47, 48, 49, 55, 56, 66, 67, 68, 69, 70, 71, 74, 75, 77, 81, 82, 86, 87, 89, 91, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 111, 112, 113, 114, 115, 116, 117, 118, 121, 122, 123, 124, 127, 128, 129, 131, 133, 138, 139, 140, 141, 142, 144, 146, 147, 148, 149, 164, 169, 172, 224 plasticity, 97, 132, 141, 142 plastics, 149 platform, 79 playing, 46, 80, 226 polar, vii, viii, 3, 6, 8, 10, 42, 63, 67, 74, 78, 81, 83, 90, 91, 95, 96, 97, 98, 109, 110, 111, 112, 113, 116, 140, 145, 157, 174, 176, 192, 193, 194, 195, 196, 197, 201, 205, 222, 226, 236, 237, 242, 248 polarization, 123, 248 politics, 231 pollen, 70 pollutants, 15 pollution, vii, ix, 2, 4, 5, 7, 10, 82, 91, 110, 222, 223, 224, 226, 228 polycarbonate, 100 polymer, 95 ponds, 16, 47, 51, 53, 54, 56, 91, 230 pools, 16, 47, 49, 91, 99 population, 48, 50, 55, 58, 62, 66, 84, 222, 223, 225, 226, 228, 230 population control, 223 population density, 50 positive correlation, 98, 114, 140 positive feedback, 225, 231 power plants, 226, 230 precipitation, 39, 40, 42, 43, 46, 70, 75, 77, 79, 80, 108, 131, 141, 164, 204, 218, 235, 237, 241, 248 preparation, iv pressure gradient, 200 prevention, 111 principles, 247 probability, 246 probe, 7 producers, 11, 49, 59, 80, 226 profit, 230 project, 34, 217 prokaryotes, 164 prokaryotic cell, 62 propagation, 189, 227, 228, 230, 235

257

Index protection, 72, 74, 75, 80, 95, 97, 98, 105, 110, 113, 115, 116, 117, 131, 132, 140, 142 protective mechanisms, 107 protective role, 97, 125 proteins, 72, 91, 100, 118, 231 protoplasm, 71 publishing, ix, xv pure water, 4, 222 pyrimidine, 116, 119, 120, 126

Q quality control, 212 quartz, 49 quasi-equilibrium, 180, 194 quercetin, 113, 114

R race, 8, 223 radar, 10, 201, 248 Radiation, v, 16, 71, 72, 83, 85, 104, 105, 107, 123, 144, 203, 212 radiation damage, 99, 128 radical formation, 123 radicals, 99 radio, 1, 4, 233, 237, 248 radius, 14, 186, 229, 234 rainfall, 7, 17, 77, 80, 141, 226 reaction center, 102 reactions, 66, 223, 228 reactive oxygen, 111 reactivity, 9 real time, 238 reality, 174, 230 receptors, 72, 121 recognition, 118, 132 recommendations, iv recovery, 105 recycling, 221, 223, 230, 231 reform, 222, 223 regenerate, 120 regions of the world, 150, 159 regression, 180, 200 regression line, 180 rehydration, 142, 143 rejection, 14, 28 religion, 223 remote sensing, 8, 33, 44, 199, 202 repair, 99, 103, 107, 111, 112, 113, 115, 116, 117, 118, 119, 120, 121, 122, 124, 126, 128, 140, 144 replication, 116, 117, 118 reproduction, 40, 81

requirements, 4, 68 researchers, viii, 6, 7, 90, 157 residues, 221, 222, 228 resilience, 121 resistance, 62, 97, 125, 150 resources, 75, 80, 87, 228 respiration, 75, 77, 82, 85, 123, 143, 164, 172 response, 32, 68, 85, 91, 95, 97, 98, 101, 104, 105, 106, 113, 122, 125, 126, 127, 129, 132, 139, 140, 146, 147, 148, 160, 164, 169, 172, 174, 176, 180, 183, 184, 187, 196, 203, 206, 219 restoration, 118 risk, 7, 116, 225 rods, 149 room temperature, 167 root, 11, 77 root system, 11 roots, 164 rotifers, 47, 50, 51, 59 roughness, 202 runoff, 225 rural development, 231 Russia, xi, xii, xiii, 7, 39, 173, 224

S safety, 234, 247 salinity, 222 salt concentration, 170 saturation, 75, 77, 80, 169 scale system, 173, 178, 194 scarcity, 169 scatter, 175 scavengers, 97 school, 223 science, viii, 3, 4, 5, 17, 27, 32, 35 scientific observation, 89 scope, 139 sea level, 7, 8, 40, 43, 149, 173, 177, 189, 195, 197, 222, 225, 226, 227, 231 seasonal changes, 142 seasonal flu, 14 secondary metabolism, 100 secrete, 97, 99 security, 132 sediment, 58, 66 sediments, 44, 48, 51, 58, 63, 86 seed, 112, 138 seedlings, 103, 123, 124, 128, 145 selectivity, 119 sensing, 44, 82, 236, 248 sensitivity, 32, 101, 102, 126 sensors, 202 seta, 53

258

Index

shade, 97, 163, 165, 166, 169, 170, 171 shape, vii, 2, 56, 68, 78, 88, 234 shear, 23 sheep, 41 shelter, 80, 132, 223 shoot, 112 shoots, 142 showing, 20, 44, 63, 68, 73, 78, 97, 111, 120, 142, 158, 174, 200, 224, 242 shrubs, 100 signals, 17, 22, 234, 241, 248 signs, 224 silica, 167 simulation, 196 simulations, 34 skin, 4, 57 social welfare, 5 sociology, 223 software, 238 SOI, 189, 190, 191, 192, 193 solution, 167, 221, 234, 237, 238, 241, 242, 247 South Africa, 3, 13, 18, 85 South America, 2, 3, 15, 105, 110, 114, 127, 135, 136, 137, 138, 144, 146 Southeast Asia, 225 Spain, 83 specialists, 133 speciation, 149, 157, 160 species richness, 49 specific heat, 16, 211 speculation, 10 spin, 123 spine, 132 sponge, 170 spore, 99 Spring, 43, 204, 210 St. Petersburg, xi, xii, xiii, 39 stability, 14, 15, 20, 35, 67, 85 stabilizers, 97 staff members, xv standard deviation, 246 state, 9, 10, 55, 63, 95, 115, 119, 120, 123, 124, 150, 164, 169, 180, 194, 201, 238, 239 states, 172, 230, 240 statistics, 31, 246 sterile, 149 stimulus, 164 stomata, 77, 164 storage, 97, 142 storms, 4, 7, 8, 10, 42, 43, 74, 233, 235, 241, 248 stress, 62, 91, 97, 100, 107, 112, 113, 115, 116, 122, 123, 124, 127, 163, 164, 169, 171, 172

structure, 4, 7, 24, 34, 40, 48, 77, 84, 88, 101, 112, 114, 121, 145, 179, 202, 203, 215, 216, 217, 219, 222, 248 style, 226 substitution, 112, 178 substrate, 39, 75, 77, 81, 121, 127 substrates, 49, 50, 66, 149 succession, 50, 73 Sun, 7, 16, 18, 22, 108, 192, 195, 230, 233 supplementation, 112 suppression, 100 surface area, 90 surface energy, 37, 203, 218, 219 surface layer, 16, 61, 173, 178, 194, 219 survival, 16, 25, 40, 41, 45, 55, 67, 68, 71, 80, 81, 107, 112, 113, 118, 131, 139, 140, 171, 222, 226 survival rate, 71 suspense, 2 sustainability, 221 Sweden, 87, 90 symbiosis, 96 synthesis, 67, 115, 140

T target, 116, 142 taxa, 138, 149, 150, 151, 152, 153, 157, 158, 166 TBP, 117 teams, 31 techniques, 44, 248 technologies, 9 technology, viii, ix, 223 technology transfer, ix temperature, 3, 5, 7, 9, 10, 11, 15, 16, 17, 24, 31, 34, 39, 41, 43, 45, 50, 51, 58, 59, 67, 68, 69, 74, 79, 84, 85, 86, 91, 97, 102, 106, 107, 108, 112, 122, 131, 132, 141, 142, 144, 146, 147, 148, 170, 174, 178, 180, 181, 182, 183, 184, 196, 197, 200, 201, 203, 204, 206, 208, 209, 210, 211, 213, 216, 217, 218, 219, 222, 224, 226 temperature dependence, 68 terrestrial ecosystems, 73, 101, 104, 122, 127, 143, 147 territorial, 58 territory, 57 testing, 97, 216, 218 TGA, 124 thermal energy, 228 thermodynamics, 230 thinning, 89 thymine, 124, 125 time periods, 113, 242 time series, 68, 102, 213

259

Index tin, 4 tissue, 69, 117, 168, 169, 170 total energy, 174 toxic effect, 100 trajectory, 208 transcription, 116, 117, 119 transcription factors, 117, 119 transformation, 237 transgression, 40 translation, 84 transmission, 4, 116, 118 transparency, 43 transpiration, 67, 70 transport, 7, 14, 28, 34, 36, 78, 99, 164, 200 transportation, 3, 4, 22, 70 treatment, 101 triggers, 17, 118 tropical storms, 224 tryptophan, 120, 125 tundra, 82 turbulence, 20, 24, 66, 75, 85, 201, 202, 211 turbulent mixing, 17, 46 turgor, 116, 163, 165, 167, 168, 169, 170, 172

U United Kingdom, xii, 33, 82, 85, 104, 218, 233 ultrastructure, 100 uniform, 108 unique features, vii, 13 United, 84, 224, 225 United Nations, 84, 224, 225 universe, 2, 7 uranium, 4 USA, 101, 102, 103, 105, 128, 202, 203, 231 USSR, 144 Ultra-Violet (UV), v, viii, ix, 6, 40, 43, 44, 46, 47, 64, 67, 72, 73, 79, 81, 84, 87, 89, 91, 95, 97, 98, 99, 100, 101, 102, 103, 104, 105, 107, 110, 111, 112, 113, 115, 116, 117, 118, 119, 121, 122, 123, 124, 125, 126, 127, 128, 131, 139, 140, 143, 144, 145, 146, 147, 231, 248 UV irradiation, 139 UV light, 43, 122 UV radiation, 6, 47, 72, 91, 96, 97, 98, 100, 104, 107, 115, 119, 122, 125, 128, 140 UV-radiation, 96, 101

V valence, 118, 128 Valencia, 83 validation, 32, 200

vapor, vii, 14, 15, 84 variables, 121, 123, 144, 203, 219 variations, 36, 51, 84, 96, 174, 176, 180, 183, 195, 196, 197, 201, 206, 208, 213, 218, 219, 222, 225, 228, 242 varieties, 40, 47, 108, 133 vector, 186, 238, 239 vegetation, 11, 34, 41, 50, 62, 63, 66, 67, 71, 72, 74, 84, 87, 95, 96, 101, 108, 121, 122, 124, 125, 139, 145 vehicles, 226 velocity, 7, 9, 10, 16, 22, 174, 201, 205, 206, 211, 215, 234, 238, 239, 242 ventilation, 35 vertebrates, 47, 57, 74, 85, 118 Viking, 248

W Washington, 145, 195, 227, 231, 248 waste, 223 water ecosystems, 40 water quality, 34, 84 water resources, 223 water shortages, 225 water vapor, vii, 15, 16, 17, 224, 226 wavelengths, 8, 91, 110, 113, 116, 236 wealth, 3 weather patterns, 222 web, 135, 237 websites, 27 Western Australia, 37 Western Europe, 225 whales, 11, 57 wild type, 117 wildlife, 225 wind speeds, 24, 131, 202 windstorms, 7 workers, 55, 58, 62, 68, 70, 74 worldwide, 223, 224, 242, 248

X xylem, 164

Y Yale University, 82 yeast, 47, 58 yield, 112, 121

Z zinc, 4

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